47dc332258
### What changes were proposed in this pull request? 1. Replace `SimpleDateFormat` by `FastDateFormat` as the legacy formatter of `FractionTimestampFormatter`. 2. Optimise `LegacyFastTimestampFormatter` for `java.sql.Timestamp` w/o fractional part. ### Why are the changes needed? 1. By default `HiveResult`.`hiveResultString` retrieves timestamps values as instances of `java.sql.Timestamp`, and uses the legacy parser `SimpleDateFormat` to convert the timestamps to strings. After the fix https://github.com/apache/spark/pull/28024, the fractional formatter and its companion - legacy formatter `SimpleDateFormat` are created per every value. By switching from `LegacySimpleTimestampFormatter` to `LegacyFastTimestampFormatter`, we can utilize the internal cache of `FastDateFormat`, and avoid parsing the default pattern `yyyy-MM-dd HH:mm:ss`. 2. The second change in the method `def format(ts: Timestamp): String` of `LegacyFastTimestampFormatter` is needed to optimize the formatter for patterns without the fractional part and avoid conversions to microseconds. ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? By existing tests in `TimestampFormatter`. Closes #28678 from MaxGekk/fastdateformat-as-legacy-frac-formatter. Authored-by: Max Gekk <max.gekk@gmail.com> Signed-off-by: Wenchen Fan <wenchen@databricks.com> |
||
|---|---|---|
| .. | ||
| benchmarks | ||
| src | ||
| pom.xml | ||