[MCOL-3410] Remove unused parts of unused query text in GROUP BY handler processing. Created: 2019-07-29 Updated: 2021-04-19 Resolved: 2020-10-29 |
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| Status: | Closed |
| Project: | MariaDB ColumnStore |
| Component/s: | MDB Plugin |
| Affects Version/s: | 1.2.3, 1.2.5 |
| Fix Version/s: | 5.4.1 |
| Type: | Bug | Priority: | Major |
| Reporter: | Roman | Assignee: | Roman |
| Resolution: | Won't Do | Votes: | 1 |
| Labels: | None | ||
| Description |
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ColumnStore VTABLE processing mode heavily depends on query text rewrite. Connector code uses strings for parts of the rewritten query text. GROUP BY Handler doesn't need this rewrites though GBH processing part still contains unused and sometimes empty parts of rewritten query. This could cause unexpected server crashes for queries with complex expression in a projection list like described in the bug linked. |
| Comments |
| Comment by Valerii Kravchuk [ 2020-07-24 ] |
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Do we have any progress or target version for the fix? |
| Comment by Roman [ 2020-07-24 ] |
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No, we don't yet. However here is the workaround: 1.5 version have a configurable setting that allows to avoid GROUP BY handler thus this issue doesn't affect the query processing. |
| Comment by Roman [ 2020-10-09 ] |
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nicklamb I believe that 1.5 is not affected by he issue itself however the session variable to disable group by handler is columnstore_group_by_handler that is enabled by default. |
| Comment by Todd Stoffel (Inactive) [ 2020-10-29 ] |
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An upgrade to 5.4.1 is recommended. |