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Standardizing SQL function docs (#12091) 

* fix typos in SQL function docs

* more code

* Update docs/querying/sql.md

Co-authored-by: Frank Chen <frankchen@apache.org>

* Update docs/querying/sql.md

Co-authored-by: Frank Chen <frankchen@apache.org>

* Update docs/querying/sql.md

Co-authored-by: Frank Chen <frankchen@apache.org>

* Update docs/querying/sql.md

Co-authored-by: Frank Chen <frankchen@apache.org>

* Update docs/querying/sql.md

Co-authored-by: Frank Chen <frankchen@apache.org>

* a few more expr, fixes

* more fixes

* quote TIME_SHIFT

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* Update docs/querying/sql.md

Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>

* undo header change

Co-authored-by: Frank Chen <frankchen@apache.org>
Co-authored-by: Victoria Lim <vtlim@users.noreply.github.com>
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@ -297,7 +297,7 @@ In the default value mode (`true`), Druid treats NULLs and empty strings interch
standard. In this mode Druid SQL only has partial support for NULLs. For example, the expressions `col IS NULL` and standard. In this mode Druid SQL only has partial support for NULLs. For example, the expressions `col IS NULL` and
`col = ''` are equivalent, and both will evaluate to true if `col` contains an empty string. Similarly, the expression `col = ''` are equivalent, and both will evaluate to true if `col` contains an empty string. Similarly, the expression
`COALESCE(col1, col2)` will return `col2` if `col1` is an empty string. While the `COUNT(*)` aggregator counts all rows, `COALESCE(col1, col2)` will return `col2` if `col1` is an empty string. While the `COUNT(*)` aggregator counts all rows,
the `COUNT(expr)` aggregator will count the number of rows where expr is neither null nor the empty string. Numeric the `COUNT(expr)` aggregator will count the number of rows where `expr` is neither null nor the empty string. Numeric
columns in this mode are not nullable; any null or missing values will be treated as zeroes. columns in this mode are not nullable; any null or missing values will be treated as zeroes.
In SQL compatible mode (`false`), NULLs are treated more closely to the SQL standard. The property affects both storage In SQL compatible mode (`false`), NULLs are treated more closely to the SQL standard. The property affects both storage
@ -340,20 +340,20 @@ In the aggregation functions supported by Druid, only `COUNT`, `ARRAY_AGG`, and
|Function|Notes|Default| |Function|Notes|Default|
|--------|-----|-------| |--------|-----|-------|
|`COUNT(*)`|Counts the number of rows.|`0`| |`COUNT(*)`|Counts the number of rows.|`0`|
|`COUNT(DISTINCT expr)`|Counts distinct values of expr.<br><br>When "useApproximateCountDistinct" is set to "true" (the default), this is an alias for APPROX_COUNT_DISTINCT. The specific algorithm that will be used depends on the value of [`druid.sql.approxCountDistinct.function`](../configuration/index.md#sql). In this mode, you can could strings, numbers, or prebuilt sketches. If counting prebuilt sketches, the prebuilt sketch type must match the selected algorithm.<br><br>When "useApproximateCountDistinct" is set to "false", the computation will be exact. In this case, expr must be string or numeric, since exact counts are not possible using prebuilt sketches. In exact mode, only one distinct count per query is permitted unless "useGroupingSetForExactDistinct" is enabled.| |`COUNT(DISTINCT expr)`|Counts distinct values of `expr`.<br><br>When `useApproximateCountDistinct` is set to "true" (the default), this is an alias for `APPROX_COUNT_DISTINCT`. The specific algorithm depends on the value of [`druid.sql.approxCountDistinct.function`](../configuration/index.md#sql). In this mode, you can use strings, numbers, or prebuilt sketches. If counting prebuilt sketches, the prebuilt sketch type must match the selected algorithm.<br><br>When `useApproximateCountDistinct` is set to "false", the computation will be exact. In this case, `expr` must be string or numeric, since exact counts are not possible using prebuilt sketches. In exact mode, only one distinct count per query is permitted unless `useGroupingSetForExactDistinct` is enabled.|`0`|
|`SUM(expr)`|Sums numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| |`SUM(expr)`|Sums numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`|
|`MIN(expr)`|Takes the minimum of numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `9223372036854775807` (maximum LONG value)| |`MIN(expr)`|Takes the minimum of numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `9223372036854775807` (maximum LONG value)|
|`MAX(expr)`|Takes the maximum of numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `-9223372036854775808` (minimum LONG value)| |`MAX(expr)`|Takes the maximum of numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `-9223372036854775808` (minimum LONG value)|
|`AVG(expr)`|Averages numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`| |`AVG(expr)`|Averages numbers.|`null` if `druid.generic.useDefaultValueForNull=false`, otherwise `0`|
|`APPROX_COUNT_DISTINCT(expr)`|Counts distinct values of expr using an approximate algorithm. The expr can be a regular column or a prebuilt sketch column.<br><br>The specific algorithm that will be used depends on the value of [`druid.sql.approxCountDistinct.function`](../configuration/index.md#sql). By default, this is `APPROX_COUNT_DISTINCT_BUILTIN`. If the [DataSketches extension](../development/extensions-core/datasketches-extension.md) is loaded, this can also be set to `APPROX_COUNT_DISTINCT_DS_HLL` or `APPROX_COUNT_DISTINCT_DS_THETA`.<br><br>When run on prebuilt sketch columns, the sketch column type must match the implementation of this function. For example: when `druid.sql.approxCountDistinct.function` is set to `APPROX_COUNT_DISTINCT_BUILTIN`, this function will be able to run on prebuilt hyperUnique columns, but not on prebuilt HLLSketchBuild columns.| |`APPROX_COUNT_DISTINCT(expr)`|Counts distinct values of `expr` using an approximate algorithm. The `expr` can be a regular column or a prebuilt sketch column.<br><br>The specific algorithm depends on the value of [`druid.sql.approxCountDistinct.function`](../configuration/index.md#sql). By default, this is `APPROX_COUNT_DISTINCT_BUILTIN`. If the [DataSketches extension](../development/extensions-core/datasketches-extension.md) is loaded, you can set it to `APPROX_COUNT_DISTINCT_DS_HLL` or `APPROX_COUNT_DISTINCT_DS_THETA`.<br><br>When run on prebuilt sketch columns, the sketch column type must match the implementation of this function. For example: when `druid.sql.approxCountDistinct.function` is set to `APPROX_COUNT_DISTINCT_BUILTIN`, this function runs on prebuilt hyperUnique columns, but not on prebuilt HLLSketchBuild columns.|
|`APPROX_COUNT_DISTINCT_BUILTIN(expr)`|_Usage note:_ consider using `APPROX_COUNT_DISTINCT_DS_HLL` instead, which offers better accuracy in many cases.<br/><br/>Counts distinct values of expr using Druid's built-in "cardinality" or "hyperUnique" aggregators, which implement a variant of [HyperLogLog](http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf). The expr can be a string, number, or prebuilt hyperUnique column. This is always approximate, regardless of the value of "useApproximateCountDistinct".| |`APPROX_COUNT_DISTINCT_BUILTIN(expr)`|_Usage note:_ consider using `APPROX_COUNT_DISTINCT_DS_HLL` instead, which offers better accuracy in many cases.<br/><br/>Counts distinct values of `expr` using Druid's built-in "cardinality" or "hyperUnique" aggregators, which implement a variant of [HyperLogLog](http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf). The `expr` can be a string, a number, or a prebuilt hyperUnique column. This is always approximate, regardless of the value of `useApproximateCountDistinct`.|
|`APPROX_COUNT_DISTINCT_DS_HLL(expr, [lgK, tgtHllType])`|Counts distinct values of expr, which can be a regular column or an [HLL sketch](../development/extensions-core/datasketches-hll.md) column. Results are always approximate, regardless of the value of [`useApproximateCountDistinct`](#connection-context). The `lgK` and `tgtHllType` parameters here are, like the equivalents in the [aggregator](../development/extensions-core/datasketches-hll.md#aggregators), described in the HLL sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function. See also `COUNT(DISTINCT expr)`. |`0`| |`APPROX_COUNT_DISTINCT_DS_HLL(expr, [lgK, tgtHllType])`|Counts distinct values of `expr`, which can be a regular column or an [HLL sketch](../development/extensions-core/datasketches-hll.md) column. Results are always approximate, regardless of the value of [`useApproximateCountDistinct`](#connection-context). The `lgK` and `tgtHllType` parameters here are, like the equivalents in the [aggregator](../development/extensions-core/datasketches-hll.md#aggregators), described in the HLL sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function. See also `COUNT(DISTINCT expr)`. |`0`|
|`APPROX_COUNT_DISTINCT_DS_THETA(expr, [size])`|Counts distinct values of expr, which can be a regular column or a [Theta sketch](../development/extensions-core/datasketches-theta.md) column. Results are always approximate, regardless of the value of [`useApproximateCountDistinct`](#connection-context). The `size` parameter is described in the Theta sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function. See also `COUNT(DISTINCT expr)`. |`0`| |`APPROX_COUNT_DISTINCT_DS_THETA(expr, [size])`|Counts distinct values of `expr`, which can be a regular column or a [Theta sketch](../development/extensions-core/datasketches-theta.md) column. Results are always approximate, regardless of the value of [`useApproximateCountDistinct`](#connection-context). The `size` parameter is described in the Theta sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function. See also `COUNT(DISTINCT expr)`. |`0`|
|`DS_HLL(expr, [lgK, tgtHllType])`|Creates an [HLL sketch](../development/extensions-core/datasketches-hll.md) on the values of expr, which can be a regular column or a column containing HLL sketches. The `lgK` and `tgtHllType` parameters are described in the HLL sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function.|`'0'` (STRING)| |`DS_HLL(expr, [lgK, tgtHllType])`|Creates an [HLL sketch](../development/extensions-core/datasketches-hll.md) on the values of `expr`, which can be a regular column or a column containing HLL sketches. The `lgK` and `tgtHllType` parameters are described in the HLL sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function.|`'0'` (STRING)|
|`DS_THETA(expr, [size])`|Creates a [Theta sketch](../development/extensions-core/datasketches-theta.md) on the values of expr, which can be a regular column or a column containing Theta sketches. The `size` parameter is described in the Theta sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function.|`'0.0'` (STRING)| |`DS_THETA(expr, [size])`|Creates a [Theta sketch](../development/extensions-core/datasketches-theta.md) on the values of `expr`, which can be a regular column or a column containing Theta sketches. The `size` parameter is described in the Theta sketch documentation. The [DataSketches extension](../development/extensions-core/datasketches-extension.md) must be loaded to use this function.|`'0.0'` (STRING)|
|`APPROX_QUANTILE(expr, probability, [resolution])`|_Deprecated._ Use `APPROX_QUANTILE_DS` instead, which provides a superior distribution-independent algorithm with formal error guarantees.<br/><br/>Computes approximate quantiles on numeric or [approxHistogram](../development/extensions-core/approximate-histograms.md#approximate-histogram-aggregator) exprs. The "probability" should be between 0 and 1 (exclusive). The "resolution" is the number of centroids to use for the computation. Higher resolutions will give more precise results but also have higher overhead. If not provided, the default resolution is 50. The [approximate histogram extension](../development/extensions-core/approximate-histograms.md) must be loaded to use this function.|`NaN`| |`APPROX_QUANTILE(expr, probability, [resolution])`|_Deprecated._ Use `APPROX_QUANTILE_DS` instead, which provides a superior distribution-independent algorithm with formal error guarantees.<br/><br/>Computes approximate quantiles on numeric or [approxHistogram](../development/extensions-core/approximate-histograms.md#approximate-histogram-aggregator) expressions. `probability` should be between 0 and 1, exclusive. `resolution` is the number of centroids to use for the computation. Higher resolutions will give more precise results but also have higher overhead. If not provided, the default resolution is 50. Load the [approximate histogram extension](../development/extensions-core/approximate-histograms.md) to use this function.|`NaN`|
|`APPROX_QUANTILE_DS(expr, probability, [k])`|Computes approximate quantiles on numeric or [Quantiles sketch](../development/extensions-core/datasketches-quantiles.md) exprs. Allowable "probability" values are between 0 and 1, exclusive. The `k` parameter is described in the Quantiles sketch documentation. You must load [DataSketches extension](../development/extensions-core/datasketches-extension.md) to use this function.<br/><br/>See the [known issue](#a-known-issue-with-approximate-functions-based-on-data-sketches) with this function.|`NaN`| |`APPROX_QUANTILE_DS(expr, probability, [k])`|Computes approximate quantiles on numeric or [Quantiles sketch](../development/extensions-core/datasketches-quantiles.md) expressions. Allowable `probability` values are between 0 and 1, exclusive. The `k` parameter is described in the Quantiles sketch documentation. You must load [DataSketches extension](../development/extensions-core/datasketches-extension.md) to use this function.<br/><br/>See the [known issue](#a-known-issue-with-approximate-functions-based-on-data-sketches) with this function.|`NaN`|
|`APPROX_QUANTILE_FIXED_BUCKETS(expr, probability, numBuckets, lowerLimit, upperLimit, [outlierHandlingMode])`|Computes approximate quantiles on numeric or [fixed buckets histogram](../development/extensions-core/approximate-histograms.md#fixed-buckets-histogram) exprs. The "probability" should be between 0 and 1 (exclusive). The `numBuckets`, `lowerLimit`, `upperLimit`, and `outlierHandlingMode` parameters are described in the fixed buckets histogram documentation. The [approximate histogram extension](../development/extensions-core/approximate-histograms.md) must be loaded to use this function.|`0.0`| |`APPROX_QUANTILE_FIXED_BUCKETS(expr, probability, numBuckets, lowerLimit, upperLimit, [outlierHandlingMode])`|Computes approximate quantiles on numeric or [fixed buckets histogram](../development/extensions-core/approximate-histograms.md#fixed-buckets-histogram) expressions. `probability` should be between 0 and 1, exclusive. The `numBuckets`, `lowerLimit`, `upperLimit`, and `outlierHandlingMode` parameters are described in the fixed buckets histogram documentation. Load the [approximate histogram extension](../development/extensions-core/approximate-histograms.md) to use this function.|`0.0`|
|`DS_QUANTILES_SKETCH(expr, [k])`|Creates a [Quantiles sketch](../development/extensions-core/datasketches-quantiles.md) on the values of `expr`, which can be a regular column or a column containing quantiles sketches. The `k` parameter is described in the Quantiles sketch documentation. You must load the [DataSketches extension](../development/extensions-core/datasketches-extension.md) to use this function.<br/><br/>See the [known issue](#a-known-issue-with-approximate-functions-based-on-data-sketches) with this function.|`'0'` (STRING)| |`DS_QUANTILES_SKETCH(expr, [k])`|Creates a [Quantiles sketch](../development/extensions-core/datasketches-quantiles.md) on the values of `expr`, which can be a regular column or a column containing quantiles sketches. The `k` parameter is described in the Quantiles sketch documentation. You must load the [DataSketches extension](../development/extensions-core/datasketches-extension.md) to use this function.<br/><br/>See the [known issue](#a-known-issue-with-approximate-functions-based-on-data-sketches) with this function.|`'0'` (STRING)|
|`BLOOM_FILTER(expr, numEntries)`|Computes a bloom filter from values produced by `expr`, with `numEntries` maximum number of distinct values before false positive rate increases. See [bloom filter extension](../development/extensions-core/bloom-filter.md) documentation for additional details.|Empty base64 encoded bloom filter STRING| |`BLOOM_FILTER(expr, numEntries)`|Computes a bloom filter from values produced by `expr`, with `numEntries` maximum number of distinct values before false positive rate increases. See [bloom filter extension](../development/extensions-core/bloom-filter.md) documentation for additional details.|Empty base64 encoded bloom filter STRING|
|`TDIGEST_QUANTILE(expr, quantileFraction, [compression])`|Builds a T-Digest sketch on values produced by `expr` and returns the value for the quantile. Compression parameter (default value 100) determines the accuracy and size of the sketch. Higher compression means higher accuracy but more space to store sketches. See [t-digest extension](../development/extensions-contrib/tdigestsketch-quantiles.md) documentation for additional details.|`Double.NaN`| |`TDIGEST_QUANTILE(expr, quantileFraction, [compression])`|Builds a T-Digest sketch on values produced by `expr` and returns the value for the quantile. Compression parameter (default value 100) determines the accuracy and size of the sketch. Higher compression means higher accuracy but more space to store sketches. See [t-digest extension](../development/extensions-contrib/tdigestsketch-quantiles.md) documentation for additional details.|`Double.NaN`|
@ -398,30 +398,30 @@ to FLOAT. At runtime, Druid will widen 32-bit floats to 64-bit for most expressi
|`PI`|Constant Pi.| |`PI`|Constant Pi.|
|`ABS(expr)`|Absolute value.| |`ABS(expr)`|Absolute value.|
|`CEIL(expr)`|Ceiling.| |`CEIL(expr)`|Ceiling.|
|`EXP(expr)`|e to the power of expr.| |`EXP(expr)`|e to the power of `expr`.|
|`FLOOR(expr)`|Floor.| |`FLOOR(expr)`|Floor.|
|`LN(expr)`|Logarithm (base e).| |`LN(expr)`|Logarithm (base e).|
|`LOG10(expr)`|Logarithm (base 10).| |`LOG10(expr)`|Logarithm (base 10).|
|`POWER(expr, power)`|expr to a power.| |`POWER(expr, power)`|`expr` raised to the power of `power`.|
|`SQRT(expr)`|Square root.| |`SQRT(expr)`|Square root.|
|`TRUNCATE(expr[, digits])`|Truncate expr to a specific number of decimal digits. If digits is negative, then this truncates that many places to the left of the decimal point. Digits defaults to zero if not specified.| |`TRUNCATE(expr, [digits])`|Truncate `expr` to a specific number of decimal digits. If digits is negative, then this truncates that many places to the left of the decimal point. Digits defaults to zero if not specified.|
|`TRUNC(expr[, digits])`|Synonym for `TRUNCATE`.| |`TRUNC(expr, [digits])`|Alias for `TRUNCATE`.|
|`ROUND(expr[, digits])`|`ROUND(x, y)` would return the value of the x rounded to the y decimal places. While x can be an integer or floating-point number, y must be an integer. The type of the return value is specified by that of x. y defaults to 0 if omitted. When y is negative, x is rounded on the left side of the y decimal points. If `expr` evaluates to either `NaN`, `expr` will be converted to 0. If `expr` is infinity, `expr` will be converted to the nearest finite double. | |`ROUND(expr, [digits])`|`ROUND(x, y)` would return the value of the x rounded to the y decimal places. While x can be an integer or floating-point number, y must be an integer. The type of the return value is specified by that of x. y defaults to 0 if omitted. When y is negative, x is rounded on the left side of the y decimal points. If `expr` evaluates to either `NaN`, `expr` will be converted to 0. If `expr` is infinity, `expr` will be converted to the nearest finite double. |
|`x + y`|Addition.| |`x + y`|Addition.|
|`x - y`|Subtraction.| |`x - y`|Subtraction.|
|`x * y`|Multiplication.| |`x * y`|Multiplication.|
|`x / y`|Division.| |`x / y`|Division.|
|`MOD(x, y)`|Modulo (remainder of x divided by y).| |`MOD(x, y)`|Modulo (remainder of x divided by y).|
|`SIN(expr)`|Trigonometric sine of an angle expr.| |`SIN(expr)`|Trigonometric sine of an angle `expr`.|
|`COS(expr)`|Trigonometric cosine of an angle expr.| |`COS(expr)`|Trigonometric cosine of an angle `expr`.|
|`TAN(expr)`|Trigonometric tangent of an angle expr.| |`TAN(expr)`|Trigonometric tangent of an angle `expr`.|
|`COT(expr)`|Trigonometric cotangent of an angle expr.| |`COT(expr)`|Trigonometric cotangent of an angle `expr`.|
|`ASIN(expr)`|Arc sine of expr.| |`ASIN(expr)`|Arc sine of `expr`.|
|`ACOS(expr)`|Arc cosine of expr.| |`ACOS(expr)`|Arc cosine of `expr`.|
|`ATAN(expr)`|Arc tangent of expr.| |`ATAN(expr)`|Arc tangent of `expr`.|
|`ATAN2(y, x)`|Angle theta from the conversion of rectangular coordinates (x, y) to polar * coordinates (r, theta).| |`ATAN2(y, x)`|Angle theta from the conversion of rectangular coordinates (x, y) to polar * coordinates (r, theta).|
|`DEGREES(expr)`|Converts an angle measured in radians to an approximately equivalent angle measured in degrees| |`DEGREES(expr)`|Converts an angle measured in radians to an approximately equivalent angle measured in degrees.|
|`RADIANS(expr)`|Converts an angle measured in degrees to an approximately equivalent angle measured in radians| |`RADIANS(expr)`|Converts an angle measured in degrees to an approximately equivalent angle measured in radians.|
|`BITWISE_AND(expr1, expr2)`|Returns the result of `expr1 & expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles| |`BITWISE_AND(expr1, expr2)`|Returns the result of `expr1 & expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles|
|`BITWISE_COMPLEMENT(expr)`|Returns the result of `~expr`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles| |`BITWISE_COMPLEMENT(expr)`|Returns the result of `~expr`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles|
|`BITWISE_CONVERT_DOUBLE_TO_LONG_BITS(expr)`|Converts the bits of an IEEE 754 floating-point double value to a long. If the input is not a double, it is implicitly cast to a double prior to conversion| |`BITWISE_CONVERT_DOUBLE_TO_LONG_BITS(expr)`|Converts the bits of an IEEE 754 floating-point double value to a long. If the input is not a double, it is implicitly cast to a double prior to conversion|
@ -431,9 +431,9 @@ to FLOAT. At runtime, Druid will widen 32-bit floats to 64-bit for most expressi
|`BITWISE_SHIFT_RIGHT(expr1, expr2)`|Returns the result of `expr1 >> expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles| |`BITWISE_SHIFT_RIGHT(expr1, expr2)`|Returns the result of `expr1 >> expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles|
|`BITWISE_XOR(expr1, expr2)`|Returns the result of `expr1 ^ expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles| |`BITWISE_XOR(expr1, expr2)`|Returns the result of `expr1 ^ expr2`. Double values will be implicitly cast to longs, use `BITWISE_CONVERT_DOUBLE_TO_LONG_BITS` to perform bitwise operations directly with doubles|
|`DIV(x, y)`|Returns the result of integer division of x by y | |`DIV(x, y)`|Returns the result of integer division of x by y |
|`HUMAN_READABLE_BINARY_BYTE_FORMAT(value[, precision])`| Format a number in human-readable [IEC](https://en.wikipedia.org/wiki/Binary_prefix) format. For example, HUMAN_READABLE_BINARY_BYTE_FORMAT(1048576) returns `1.00 MiB`. `precision` must be in the range of [0,3] (default: 2). | |`HUMAN_READABLE_BINARY_BYTE_FORMAT(value, [precision])`| Format a number in human-readable [IEC](https://en.wikipedia.org/wiki/Binary_prefix) format. For example, HUMAN_READABLE_BINARY_BYTE_FORMAT(1048576) returns `1.00 MiB`. `precision` must be in the range of `[0, 3]` (default: 2). |
|`HUMAN_READABLE_DECIMAL_BYTE_FORMAT(value[, precision])`| Format a number in human-readable [SI](https://en.wikipedia.org/wiki/Binary_prefix) format. HUMAN_READABLE_DECIMAL_BYTE_FORMAT(1048576) returns `1.04 MB`. `precision` must be in the range of [0,3] (default: 2). `precision` must be in the range of [0,3] (default: 2). | |`HUMAN_READABLE_DECIMAL_BYTE_FORMAT(value, [precision])`| Format a number in human-readable [SI](https://en.wikipedia.org/wiki/Binary_prefix) format. HUMAN_READABLE_DECIMAL_BYTE_FORMAT(1048576) returns `1.04 MB`. `precision` must be in the range of `[0, 3]` (default: 2). `precision` must be in the range of `[0, 3]` (default: 2). |
|`HUMAN_READABLE_DECIMAL_FORMAT(value[, precision])`| Format a number in human-readable SI format. For example, HUMAN_READABLE_DECIMAL_FORMAT(1048576) returns `1.04 M`. `precision` must be in the range of [0,3] (default: 2). | |`HUMAN_READABLE_DECIMAL_FORMAT(value, [precision])`| Format a number in human-readable SI format. For example, HUMAN_READABLE_DECIMAL_FORMAT(1048576) returns `1.04 M`. `precision` must be in the range of `[0, 3]` (default: 2). |
|`SAFE_DIVIDE(x, y)`|Returns the division of x by y guarded on division by 0. In case y is 0 it returns 0, or `null` if `druid.generic.useDefaultValueForNull=false` | |`SAFE_DIVIDE(x, y)`|Returns the division of x by y guarded on division by 0. In case y is 0 it returns 0, or `null` if `druid.generic.useDefaultValueForNull=false` |
@ -443,37 +443,37 @@ String functions accept strings, and return a type appropriate to the function.
|Function|Notes| |Function|Notes|
|--------|-----| |--------|-----|
|<code>x &#124;&#124; y</code>|Concat strings x and y.| |<code>x &#124;&#124; y</code>|Concat strings `x` and `y`.|
|`CONCAT(expr, expr...)`|Concats a list of expressions.| |`CONCAT(expr, expr...)`|Concats a list of expressions.|
|`TEXTCAT(expr, expr)`|Two argument version of CONCAT.| |`TEXTCAT(expr, expr)`|Two argument version of `CONCAT`.|
|`STRING_FORMAT(pattern[, args...])`|Returns a string formatted in the manner of Java's [String.format](https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#format-java.lang.String-java.lang.Object...-).| |`STRING_FORMAT(pattern, [args...])`|Returns a string formatted in the manner of Java's [String.format](https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#format-java.lang.String-java.lang.Object...-).|
|`LENGTH(expr)`|Length of expr in UTF-16 code units.| |`LENGTH(expr)`|Length of `expr` in UTF-16 code units.|
|`CHAR_LENGTH(expr)`|Synonym for `LENGTH`.| |`CHAR_LENGTH(expr)`|Alias for `LENGTH`.|
|`CHARACTER_LENGTH(expr)`|Synonym for `LENGTH`.| |`CHARACTER_LENGTH(expr)`|Alias for `LENGTH`.|
|`STRLEN(expr)`|Synonym for `LENGTH`.| |`STRLEN(expr)`|Alias for `LENGTH`.|
|`LOOKUP(expr, lookupName)`|Look up expr in a registered [query-time lookup table](lookups.md). Note that lookups can also be queried directly using the [`lookup` schema](#from).| |`LOOKUP(expr, lookupName)`|Look up `expr` in a registered [query-time lookup table](lookups.md). Note that lookups can also be queried directly using the [`lookup` schema](#from).|
|`LOWER(expr)`|Returns expr in all lowercase.| |`LOWER(expr)`|Returns `expr` in all lowercase.|
|`PARSE_LONG(string[, radix])`|Parses a string into a long (BIGINT) with the given radix, or 10 (decimal) if a radix is not provided.| |`PARSE_LONG(string, [radix])`|Parses a string into a long (BIGINT) with the given radix, or 10 (decimal) if a radix is not provided.|
|`POSITION(needle IN haystack [FROM fromIndex])`|Returns the index of needle within haystack, with indexes starting from 1. The search will begin at fromIndex, or 1 if fromIndex is not specified. If the needle is not found, returns 0.| |`POSITION(needle IN haystack [FROM fromIndex])`|Returns the index of needle within haystack, with indexes starting from 1. The search will begin at `fromIndex`, or 1 if `fromIndex` is not specified. If the needle is not found, returns 0.|
|`REGEXP_EXTRACT(expr, pattern, [index])`|Apply regular expression `pattern` to `expr` and extract a capture group, or `NULL` if there is no match. If index is unspecified or zero, returns the first substring that matched the pattern. The pattern may match anywhere inside `expr`; if you want to match the entire string instead, use the `^` and `$` markers at the start and end of your pattern. Note: when `druid.generic.useDefaultValueForNull = true`, it is not possible to differentiate an empty-string match from a non-match (both will return `NULL`).| |`REGEXP_EXTRACT(expr, pattern, [index])`|Apply regular expression `pattern` to `expr` and extract a capture group, or `NULL` if there is no match. If index is unspecified or zero, returns the first substring that matched the pattern. The pattern may match anywhere inside `expr`; if you want to match the entire string instead, use the `^` and `$` markers at the start and end of your pattern. Note: when `druid.generic.useDefaultValueForNull = true`, it is not possible to differentiate an empty-string match from a non-match (both will return `NULL`).|
|`REGEXP_LIKE(expr, pattern)`|Returns whether `expr` matches regular expression `pattern`. The pattern may match anywhere inside `expr`; if you want to match the entire string instead, use the `^` and `$` markers at the start and end of your pattern. Similar to [`LIKE`](#comparison-operators), but uses regexps instead of LIKE patterns. Especially useful in WHERE clauses.| |`REGEXP_LIKE(expr, pattern)`|Returns whether `expr` matches regular expression `pattern`. The pattern may match anywhere inside `expr`; if you want to match the entire string instead, use the `^` and `$` markers at the start and end of your pattern. Similar to [`LIKE`](#comparison-operators), but uses regexps instead of LIKE patterns. Especially useful in WHERE clauses.|
|`CONTAINS_STRING(<expr>, str)`|Returns true if the `str` is a substring of `expr`.| |`CONTAINS_STRING(expr, str)`|Returns true if the `str` is a substring of `expr`.|
|`ICONTAINS_STRING(<expr>, str)`|Returns true if the `str` is a substring of `expr`. The match is case-insensitive.| |`ICONTAINS_STRING(expr, str)`|Returns true if the `str` is a substring of `expr`. The match is case-insensitive.|
|`REPLACE(expr, pattern, replacement)`|Replaces pattern with replacement in expr, and returns the result.| |`REPLACE(expr, pattern, replacement)`|Replaces pattern with replacement in `expr`, and returns the result.|
|`STRPOS(haystack, needle)`|Returns the index of needle within haystack, with indexes starting from 1. If the needle is not found, returns 0.| |`STRPOS(haystack, needle)`|Returns the index of `needle` within `haystack`, with indexes starting from 1. If the `needle` is not found, returns 0.|
|`SUBSTRING(expr, index, [length])`|Returns a substring of expr starting at index, with a max length, both measured in UTF-16 code units.| |`SUBSTRING(expr, index, [length])`|Returns a substring of `expr` starting at index, with a max length, both measured in UTF-16 code units.|
|`RIGHT(expr, [length])`|Returns the rightmost length characters from expr.| |`RIGHT(expr, [length])`|Returns the rightmost length characters from `expr`.|
|`LEFT(expr, [length])`|Returns the leftmost length characters from expr.| |`LEFT(expr, [length])`|Returns the leftmost length characters from `expr`.|
|`SUBSTR(expr, index, [length])`|Synonym for SUBSTRING.| |`SUBSTR(expr, index, [length])`|Alias for SUBSTRING.|
|`TRIM([BOTH `<code>&#124;</code>` LEADING `<code>&#124;</code>` TRAILING] [<chars> FROM] expr)`|Returns expr with characters removed from the leading, trailing, or both ends of "expr" if they are in "chars". If "chars" is not provided, it defaults to " " (a space). If the directional argument is not provided, it defaults to "BOTH".| |`TRIM([BOTH `<code>&#124;</code>` LEADING `<code>&#124;</code>` TRAILING] [chars FROM] expr)`|Returns `expr` with characters removed from the leading, trailing, or both ends of "expr" if they are in "chars". If "chars" is not provided, it defaults to " " (a space). If the directional argument is not provided, it defaults to "BOTH".|
|`BTRIM(expr[, chars])`|Alternate form of `TRIM(BOTH <chars> FROM <expr>)`.| |`BTRIM(expr, [chars])`|Alternate form of `TRIM(BOTH chars FROM expr)`.|
|`LTRIM(expr[, chars])`|Alternate form of `TRIM(LEADING <chars> FROM <expr>)`.| |`LTRIM(expr, [chars])`|Alternate form of `TRIM(LEADING chars FROM expr)`.|
|`RTRIM(expr[, chars])`|Alternate form of `TRIM(TRAILING <chars> FROM <expr>)`.| |`RTRIM(expr, [chars])`|Alternate form of `TRIM(TRAILING chars FROM expr)`.|
|`UPPER(expr)`|Returns expr in all uppercase.| |`UPPER(expr)`|Returns `expr` in all uppercase.|
|`REVERSE(expr)`|Reverses expr.| |`REVERSE(expr)`|Reverses `expr`.|
|`REPEAT(expr, [N])`|Repeats expr N times| |`REPEAT(expr, [N])`|Repeats `expr` N times|
|`LPAD(expr, length[, chars])`|Returns a string of `length` from `expr` left-padded with `chars`. If `length` is shorter than the length of `expr`, the result is `expr` which is truncated to `length`. The result will be null if either `expr` or `chars` is null. If `chars` is an empty string, no padding is added, however `expr` may be trimmed if necessary.| |`LPAD(expr, length, [chars])`|Returns a string of `length` from `expr` left-padded with `chars`. If `length` is shorter than the length of `expr`, the result is `expr` which is truncated to `length`. The result will be null if either `expr` or `chars` is null. If `chars` is an empty string, no padding is added, however `expr` may be trimmed if necessary.|
|`RPAD(expr, length[, chars])`|Returns a string of `length` from `expr` right-padded with `chars`. If `length` is shorter than the length of `expr`, the result is `expr` which is truncated to `length`. The result will be null if either `expr` or `chars` is null. If `chars` is an empty string, no padding is added, however `expr` may be trimmed if necessary.| |`RPAD(expr, length, [chars])`|Returns a string of `length` from `expr` right-padded with `chars`. If `length` is shorter than the length of `expr`, the result is `expr` which is truncated to `length`. The result will be null if either `expr` or `chars` is null. If `chars` is an empty string, no padding is added, however `expr` may be trimmed if necessary.|
### Time functions ### Time functions
@ -494,21 +494,21 @@ simplest way to write literal timestamps in other time zones is to use TIME_PARS
|--------|-----| |--------|-----|
|`CURRENT_TIMESTAMP`|Current timestamp in the connection's time zone.| |`CURRENT_TIMESTAMP`|Current timestamp in the connection's time zone.|
|`CURRENT_DATE`|Current date in the connection's time zone.| |`CURRENT_DATE`|Current date in the connection's time zone.|
|`DATE_TRUNC(<unit>, <timestamp_expr>)`|Rounds down a timestamp, returning it as a new timestamp. Unit can be 'milliseconds', 'second', 'minute', 'hour', 'day', 'week', 'month', 'quarter', 'year', 'decade', 'century', or 'millennium'.| |`DATE_TRUNC(unit, timestamp_expr)`|Rounds down a timestamp, returning it as a new timestamp. Unit can be 'milliseconds', 'second', 'minute', 'hour', 'day', 'week', 'month', 'quarter', 'year', 'decade', 'century', or 'millennium'.|
|`TIME_CEIL(<timestamp_expr>, <period>, [<origin>, [<timezone>]])`|Rounds up a timestamp, returning it as a new timestamp. Period can be any ISO8601 period, like P3M (quarters) or PT12H (half-days). Specify `<origin>` as a timestamp to set the reference time for rounding. For example, `TIME_CEIL(__time, 'PT1H', TIMESTAMP '2016-06-27 00:30:00')` measures an hourly period from 00:30-01:30 instead of 00:00-01:00. See [Period granularities](granularities.md) for details on the default starting boundaries. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `CEIL` but is more flexible.| |`TIME_CEIL(timestamp_expr, period, [origin, [timezone]])`|Rounds up a timestamp, returning it as a new timestamp. Period can be any ISO8601 period, like P3M (quarters) or PT12H (half-days). Specify `origin` as a timestamp to set the reference time for rounding. For example, `TIME_CEIL(__time, 'PT1H', TIMESTAMP '2016-06-27 00:30:00')` measures an hourly period from 00:30-01:30 instead of 00:00-01:00. See [Period granularities](granularities.md) for details on the default starting boundaries. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `CEIL` but is more flexible.|
|`TIME_FLOOR(<timestamp_expr>, <period>, [<origin>, [<timezone>]])`|Rounds down a timestamp, returning it as a new timestamp. Period can be any ISO8601 period, like P3M (quarters) or PT12H (half-days). Specify `<origin>` as a timestamp to set the reference time for rounding. For example, `TIME_FLOOR(__time, 'PT1H', TIMESTAMP '2016-06-27 00:30:00')` measures an hourly period from 00:30-01:30 instead of 00:00-01:00. See [Period granularities](granularities.md) for details on the default starting boundaries. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `FLOOR` but is more flexible.| |`TIME_FLOOR(timestamp_expr, period, [origin, [timezone]])`|Rounds down a timestamp, returning it as a new timestamp. Period can be any ISO8601 period, like P3M (quarters) or PT12H (half-days). Specify `origin` as a timestamp to set the reference time for rounding. For example, `TIME_FLOOR(__time, 'PT1H', TIMESTAMP '2016-06-27 00:30:00')` measures an hourly period from 00:30-01:30 instead of 00:00-01:00. See [Period granularities](granularities.md) for details on the default starting boundaries. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `FLOOR` but is more flexible.|
|`TIME_SHIFT(<timestamp_expr>, <period>, <step>, [<timezone>])`|Shifts a timestamp by a period (step times), returning it as a new timestamp. Period can be any ISO8601 period. Step may be negative. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00".| |`TIME_SHIFT(timestamp_expr, period, step, [timezone])`|Shifts a timestamp by a period (step times), returning it as a new timestamp. Period can be any ISO8601 period. Step may be negative. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00".|
|`TIME_EXTRACT(<timestamp_expr>, [<unit>, [<timezone>]])`|Extracts a time part from expr, returning it as a number. Unit can be EPOCH, SECOND, MINUTE, HOUR, DAY (day of month), DOW (day of week), DOY (day of year), WEEK (week of [week year](https://en.wikipedia.org/wiki/ISO_week_date)), MONTH (1 through 12), QUARTER (1 through 4), or YEAR. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `EXTRACT` but is more flexible. Unit and time zone must be literals, and must be provided quoted, like `TIME_EXTRACT(__time, 'HOUR')` or `TIME_EXTRACT(__time, 'HOUR', 'America/Los_Angeles')`.| |`TIME_EXTRACT(timestamp_expr, [unit, [timezone]])`|Extracts a time part from `expr`, returning it as a number. Unit can be EPOCH, SECOND, MINUTE, HOUR, DAY (day of month), DOW (day of week), DOY (day of year), WEEK (week of [week year](https://en.wikipedia.org/wiki/ISO_week_date)), MONTH (1 through 12), QUARTER (1 through 4), or YEAR. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". This function is similar to `EXTRACT` but is more flexible. Unit and time zone must be literals, and must be provided quoted, like `TIME_EXTRACT(__time, 'HOUR')` or `TIME_EXTRACT(__time, 'HOUR', 'America/Los_Angeles')`.|
|`TIME_PARSE(<string_expr>, [<pattern>, [<timezone>]])`|Parses a string into a timestamp using a given [Joda DateTimeFormat pattern](http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html), or ISO8601 (e.g. `2000-01-02T03:04:05Z`) if the pattern is not provided. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00", and will be used as the time zone for strings that do not include a time zone offset. Pattern and time zone must be literals. Strings that cannot be parsed as timestamps will be returned as NULL.| |`TIME_PARSE(string_expr, [pattern, [timezone]])`|Parses a string into a timestamp using a given [Joda DateTimeFormat pattern](http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html), or ISO8601 (e.g. `2000-01-02T03:04:05Z`) if the pattern is not provided. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00", and will be used as the time zone for strings that do not include a time zone offset. Pattern and time zone must be literals. Strings that cannot be parsed as timestamps will be returned as NULL.|
|`TIME_FORMAT(<timestamp_expr>, [<pattern>, [<timezone>]])`|Formats a timestamp as a string with a given [Joda DateTimeFormat pattern](http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html), or ISO8601 (e.g. `2000-01-02T03:04:05Z`) if the pattern is not provided. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". Pattern and time zone must be literals.| |`TIME_FORMAT(timestamp_expr, [pattern, [timezone]])`|Formats a timestamp as a string with a given [Joda DateTimeFormat pattern](http://www.joda.org/joda-time/apidocs/org/joda/time/format/DateTimeFormat.html), or ISO8601 (e.g. `2000-01-02T03:04:05Z`) if the pattern is not provided. The time zone, if provided, should be a time zone name like "America/Los_Angeles" or offset like "-08:00". Pattern and time zone must be literals.|
|`MILLIS_TO_TIMESTAMP(millis_expr)`|Converts a number of milliseconds since the epoch into a timestamp.| |`MILLIS_TO_TIMESTAMP(millis_expr)`|Converts a number of milliseconds since the epoch into a timestamp.|
|`TIMESTAMP_TO_MILLIS(timestamp_expr)`|Converts a timestamp into a number of milliseconds since the epoch.| |`TIMESTAMP_TO_MILLIS(timestamp_expr)`|Converts a timestamp into a number of milliseconds since the epoch.|
|`EXTRACT(<unit> FROM timestamp_expr)`|Extracts a time part from expr, returning it as a number. Unit can be EPOCH, MICROSECOND, MILLISECOND, SECOND, MINUTE, HOUR, DAY (day of month), DOW (day of week), ISODOW (ISO day of week), DOY (day of year), WEEK (week of year), MONTH, QUARTER, YEAR, ISOYEAR, DECADE, CENTURY or MILLENNIUM. Units must be provided unquoted, like `EXTRACT(HOUR FROM __time)`.| |`EXTRACT(unit FROM timestamp_expr)`|Extracts a time part from `expr`, returning it as a number. Unit can be EPOCH, MICROSECOND, MILLISECOND, SECOND, MINUTE, HOUR, DAY (day of month), DOW (day of week), ISODOW (ISO day of week), DOY (day of year), WEEK (week of year), MONTH, QUARTER, YEAR, ISOYEAR, DECADE, CENTURY or MILLENNIUM. Units must be provided unquoted, like `EXTRACT(HOUR FROM __time)`.|
|`FLOOR(timestamp_expr TO <unit>)`|Rounds down a timestamp, returning it as a new timestamp. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.| |`FLOOR(timestamp_expr TO unit)`|Rounds down a timestamp, returning it as a new timestamp. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.|
|`CEIL(timestamp_expr TO <unit>)`|Rounds up a timestamp, returning it as a new timestamp. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.| |`CEIL(timestamp_expr TO unit)`|Rounds up a timestamp, returning it as a new timestamp. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.|
|`TIMESTAMPADD(<unit>, <count>, <timestamp>)`|Equivalent to `timestamp + count * INTERVAL '1' UNIT`.| |`TIMESTAMPADD(unit, count, timestamp)`|Equivalent to `timestamp + count * INTERVAL '1' UNIT`.|
|`TIMESTAMPDIFF(<unit>, <timestamp1>, <timestamp2>)`|Returns the (signed) number of `unit` between `timestamp1` and `timestamp2`. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.| |`TIMESTAMPDIFF(unit, timestamp1, timestamp2)`|Returns the (signed) number of `unit` between `timestamp1` and `timestamp2`. Unit can be SECOND, MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, or YEAR.|
|<code>timestamp_expr { + &#124; - } <interval_expr><code>|Add or subtract an amount of time from a timestamp. interval_expr can include interval literals like `INTERVAL '2' HOUR`, and may include interval arithmetic as well. This operator treats days as uniformly 86400 seconds long, and does not take into account daylight savings time. To account for daylight savings time, use TIME_SHIFT instead.| |<code>timestamp_expr { + &#124; - } interval_expr</code>|Add or subtract an amount of time from a timestamp. interval_expr can include interval literals like `INTERVAL '2' HOUR`, and may include interval arithmetic as well. This operator treats days as uniformly 86400 seconds long, and does not take into account daylight savings time. To account for daylight savings time, use `TIME_SHIFT` instead.|
### Reduction functions ### Reduction functions
@ -621,8 +621,8 @@ The [DataSketches extension](../development/extensions-core/datasketches-extensi
|`CASE WHEN boolean_expr1 THEN result1 \[ WHEN boolean_expr2 THEN result2 ... \] \[ ELSE resultN \] END`|Searched CASE.| |`CASE WHEN boolean_expr1 THEN result1 \[ WHEN boolean_expr2 THEN result2 ... \] \[ ELSE resultN \] END`|Searched CASE.|
|`NULLIF(value1, value2)`|Returns NULL if value1 and value2 match, else returns value1.| |`NULLIF(value1, value2)`|Returns NULL if value1 and value2 match, else returns value1.|
|`COALESCE(value1, value2, ...)`|Returns the first value that is neither NULL nor empty string.| |`COALESCE(value1, value2, ...)`|Returns the first value that is neither NULL nor empty string.|
|`NVL(expr,expr-for-null)`|Returns 'expr-for-null' if 'expr' is null (or empty string for string type).| |`NVL(expr, expr-for-null)`|Returns `expr-for-null` if `expr` is null (or empty string for string type).|
|`BLOOM_FILTER_TEST(<expr>, <serialized-filter>)`|Returns true if the value is contained in a Base64-serialized bloom filter. See the [Bloom filter extension](../development/extensions-core/bloom-filter.md) documentation for additional details.| |`BLOOM_FILTER_TEST(expr, serialized-filter)`|Returns true if the value of `expr` is contained in the Base64-serialized Bloom filter. See the [Bloom filter extension](../development/extensions-core/bloom-filter.md) documentation for additional details.|
## Multi-value string functions ## Multi-value string functions
@ -631,22 +631,22 @@ All 'array' references in the multi-value string function documentation can refe
|Function|Notes| |Function|Notes|
|--------|-----| |--------|-----|
| `ARRAY[expr1,expr ...]` | constructs a SQL ARRAY literal from the expression arguments, using the type of the first argument as the output array type | |`ARRAY[expr1, expr2, ...]`|Constructs a SQL ARRAY literal from the expression arguments, using the type of the first argument as the output array type.|
| `MV_FILTER_ONLY(expr, arr)` | filters multi-value `expr` to include only values contained in array `arr` | |`MV_FILTER_ONLY(expr, arr)`|Filters multi-value `expr` to include only values contained in array `arr`.|
| `MV_FILTER_NONE(expr, arr)` | filters multi-value `expr` to include no values contained in array `arr` | |`MV_FILTER_NONE(expr, arr)`|Filters multi-value `expr` to include no values contained in array `arr`.|
| `MV_LENGTH(arr)` | returns length of array expression | |`MV_LENGTH(arr)`|Returns length of array expression.|
| `MV_OFFSET(arr,long)` | returns the array element at the 0 based index supplied, or null for an out of range index| |`MV_OFFSET(arr, long)`|Returns the array element at the 0 based index supplied, or null for an out of range index.|
| `MV_ORDINAL(arr,long)` | returns the array element at the 1 based index supplied, or null for an out of range index | |`MV_ORDINAL(arr, long)`|Returns the array element at the 1 based index supplied, or null for an out of range index.|
| `MV_CONTAINS(arr,expr)` | returns 1 if the array contains the element specified by expr, or contains all elements specified by expr if expr is an array, else 0 | |`MV_CONTAINS(arr, expr)`|Returns 1 if the array contains the element specified by `expr`, or contains all elements specified by `expr` if `expr` is an array, else 0.|
| `MV_OVERLAP(arr1,arr2)` | returns 1 if arr1 and arr2 have any elements in common, else 0 | |`MV_OVERLAP(arr1, arr2)`|Returns 1 if arr1 and arr2 have any elements in common, else 0.|
| `MV_OFFSET_OF(arr,expr)` | returns the 0 based index of the first occurrence of expr in the array, or `-1` or `null` if `druid.generic.useDefaultValueForNull=false` if no matching elements exist in the array. | |`MV_OFFSET_OF(arr, expr)`|Returns the 0 based index of the first occurrence of `expr` in the array, or `-1` or `null` if `druid.generic.useDefaultValueForNull=false` if no matching elements exist in the array.|
| `MV_ORDINAL_OF(arr,expr)` | returns the 1 based index of the first occurrence of expr in the array, or `-1` or `null` if `druid.generic.useDefaultValueForNull=false` if no matching elements exist in the array. | |`MV_ORDINAL_OF(arr, expr)`|Returns the 1 based index of the first occurrence of `expr` in the array, or `-1` or `null` if `druid.generic.useDefaultValueForNull=false` if no matching elements exist in the array.|
| `MV_PREPEND(expr,arr)` | adds expr to arr at the beginning, the resulting array type determined by the type of the array | |`MV_PREPEND(expr, arr)`|Adds `expr` to `arr` at the beginning, the resulting array type determined by the type of the array.|
| `MV_APPEND(arr1,expr)` | appends expr to arr, the resulting array type determined by the type of the first array | |`MV_APPEND(arr1, expr)`|Appends `expr` to `arr`, the resulting array type determined by the type of the first array.|
| `MV_CONCAT(arr1,arr2)` | concatenates 2 arrays, the resulting array type determined by the type of the first array | |`MV_CONCAT(arr1, arr2)`|Concatenates 2 arrays, the resulting array type determined by the type of the first array.|
| `MV_SLICE(arr,start,end)` | return the subarray of arr from the 0 based index start(inclusive) to end(exclusive), or `null`, if start is less than 0, greater than length of arr or less than end| |`MV_SLICE(arr, start, end)`|Returns the subarray of `arr` from the 0 based index start(inclusive) to end(exclusive), or `null`, if start is less than 0, greater than length of arr or less than end.|
| `MV_TO_STRING(arr,str)` | joins all elements of arr by the delimiter specified by str | |`MV_TO_STRING(arr, str)`|Joins all elements of `arr` by the delimiter specified by `str`.|
| `STRING_TO_MV(str1,str2)` | splits str1 into an array on the delimiter specified by str2 | |`STRING_TO_MV(str1, str2)`|Splits `str1` into an array on the delimiter specified by `str2`.|
## Query translation ## Query translation
@ -762,7 +762,7 @@ Druid SQL uses four different native query types.
- [Scan](scan-query.md) is used for queries that do not aggregate (no GROUP BY, no DISTINCT). - [Scan](scan-query.md) is used for queries that do not aggregate (no GROUP BY, no DISTINCT).
- [Timeseries](timeseriesquery.md) is used for queries that GROUP BY `FLOOR(__time TO <unit>)` or `TIME_FLOOR(__time, - [Timeseries](timeseriesquery.md) is used for queries that GROUP BY `FLOOR(__time TO unit)` or `TIME_FLOOR(__time,
period)`, have no other grouping expressions, no HAVING or LIMIT clauses, no nesting, and either no ORDER BY, or an period)`, have no other grouping expressions, no HAVING or LIMIT clauses, no nesting, and either no ORDER BY, or an
ORDER BY that orders by same expression as present in GROUP BY. It also uses Timeseries for "grand total" queries that ORDER BY that orders by same expression as present in GROUP BY. It also uses Timeseries for "grand total" queries that
have aggregation functions but no GROUP BY. This query type takes advantage of the fact that Druid segments are sorted have aggregation functions but no GROUP BY. This query type takes advantage of the fact that Druid segments are sorted