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HHH-18043 Change the temporal arithmetic to use nanoseconds

This commit is contained in:
Christian Beikov 2024-05-02 12:44:42 +02:00 committed by Gavin King
parent 14216fc267
commit 9011d22315
2 changed files with 21 additions and 43 deletions
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31
hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SQLServerLegacyDialect.java
View File

@ -820,19 +820,10 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
return 6; //microseconds!
}
/**
* SQL server supports up to 7 decimal digits of
* fractional second precision in a datetime2,
* but unfortunately its duration arithmetic
* functions have a nasty habit of overflowing.
* So to give ourselves a little extra headroom,
* we will use {@code microsecond} as the native
* unit of precision (but even then we have to
* use tricks when calling {@code dateadd()}).
*/
@Override
public long getFractionalSecondPrecisionInNanos() {
return 1_000; //microseconds!
// return 100; // 1/10th microsecond
return 1; // Even though SQL Server only supports 1/10th microsecond precision, use nanosecond scale for easier computation
}
@Override
@ -849,7 +840,7 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
// return "(datepart(second,?2)*1000000000+datepart(nanosecond,?2))";
case SECOND:
//this should evaluate to a floating point type
return "(datepart(second,?2)+datepart(nanosecond,?2)/1e9)";
return "(datepart(second,?2)+datepart(nanosecond,?2)/1000000000)";
case EPOCH:
return "datediff_big(second, '1970-01-01', ?2)";
case WEEK:
@ -870,13 +861,11 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
// calls to dateadd() to add a whole duration
switch (unit) {
case NANOSECOND:
//Java Durations are usually the only thing
//we find expressed in nanosecond precision,
//and they can easily be very large
return "dateadd(nanosecond,?2%1000000000,dateadd(second,?2/1000000000,?3))";
case NATIVE:
//microsecond is the "native" precision
return "dateadd(microsecond,?2%1000000,dateadd(second,?2/1000000,?3))";
return "dateadd(nanosecond,?2%1000000000,dateadd(second,?2/1000000000,?3))";
// case NATIVE:
// // 1/10th microsecond is the "native" precision
// return "dateadd(nanosecond,?2%10000000,dateadd(second,?2/10000000,?3))";
default:
return "dateadd(?1,?2,?3)";
}
@ -885,7 +874,7 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
@Override
public String timestampdiffPattern(TemporalUnit unit, TemporalType fromTemporalType, TemporalType toTemporalType) {
if ( unit == TemporalUnit.NATIVE ) {//use microsecond as the "native" precision
return "datediff_big(microsecond,?2,?3)";
return "datediff_big(nanosecond,?2,?3)";
}
//datediff() returns an int, and can easily
@ -898,9 +887,9 @@ public class SQLServerLegacyDialect extends AbstractTransactSQLDialect {
@Override
public String translateDurationField(TemporalUnit unit) {
//use microsecond as the "native" precision
//use nanosecond as the "native" precision
if ( unit == TemporalUnit.NATIVE ) {
return "microsecond";
return "nanosecond";
}
return super.translateDurationField( unit );

33
hibernate-core/src/main/java/org/hibernate/dialect/SQLServerDialect.java
View File

@ -788,19 +788,10 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
return 6; //microseconds!
}
/**
* SQL server supports up to 7 decimal digits of
* fractional second precision in {@code datetime2},
* but unfortunately its duration arithmetic
* functions have a nasty habit of overflowing.
* So to give ourselves a little extra headroom,
* we will use {@code microsecond} as the native
* unit of precision (but even then we have to
* use tricks when calling {@code dateadd()}).
*/
@Override
public long getFractionalSecondPrecisionInNanos() {
return 1_000; //microseconds!
// return 100; // 1/10th microsecond
return 1; // Even though SQL Server only supports 1/10th microsecond precision, use nanosecond scale for easier computation
}
@Override
@ -817,7 +808,7 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
// return "(datepart(second,?2)*1000000000+datepart(nanosecond,?2))";
case SECOND:
//this should evaluate to a floating point type
return "(datepart(second,?2)+datepart(nanosecond,?2)/1e9)";
return "(datepart(second,?2)+datepart(nanosecond,?2)/1000000000)";
case EPOCH:
return "datediff_big(second, '1970-01-01', ?2)";
default:
@ -833,13 +824,11 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
// calls to dateadd() to add a whole duration
switch (unit) {
case NANOSECOND:
//Java Durations are usually the only thing
//we find expressed in nanosecond precision,
//and they can easily be very large
return "dateadd(nanosecond,?2%1000000000,dateadd(second,?2/1000000000,?3))";
case NATIVE:
//microsecond is the "native" precision
return "dateadd(microsecond,?2%1000000,dateadd(second,?2/1000000,?3))";
return "dateadd(nanosecond,?2%1000000000,dateadd(second,?2/1000000000,?3))";
// case NATIVE:
// // 1/10th microsecond is the "native" precision
// return "dateadd(nanosecond,?2%10000000,dateadd(second,?2/10000000,?3))";
default:
return "dateadd(?1,?2,?3)";
}
@ -848,8 +837,8 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
@Override
public String timestampdiffPattern(TemporalUnit unit, TemporalType fromTemporalType, TemporalType toTemporalType) {
if ( unit == TemporalUnit.NATIVE ) {
//use microsecond as the "native" precision
return "datediff_big(microsecond,?2,?3)";
//use nanosecond as the "native" precision
return "datediff_big(nanosecond,?2,?3)";
}
else {
//datediff() returns an int, and can easily
@ -863,9 +852,9 @@ public class SQLServerDialect extends AbstractTransactSQLDialect {
@Override
public String translateDurationField(TemporalUnit unit) {
//use microsecond as the "native" precision
//use nanosecond as the "native" precision
if ( unit == TemporalUnit.NATIVE ) {
return "microsecond";
return "nanosecond";
}
else {
return super.translateDurationField( unit );