sadikovi opened a new pull request, #40155:
URL: https://github.com/apache/spark/pull/40155
### What changes were proposed in this pull request?
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The PR fixes DB2 Limit clause syntax. Although DB2 supports LIMIT keyword,
it seems that this support varies across databases and versions and the
recommended way is to use `FETCH FIRST x ROWS ONLY`. In fact, some versions
don't support LIMIT at all. Doc:
https://www.ibm.com/docs/en/db2/11.5?topic=subselect-fetch-clause, usage
example: https://www.mullinsconsulting.com/dbu_0502.htm.
### Why are the changes needed?
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Fixes the incorrect Limit clause which could cause errors when using against
DB2 versions that don't support LIMIT.
### Does this PR introduce _any_ user-facing change?
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No.
### How was this patch tested?
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I added a unit test and an integration test to cover this functionality.
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