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Prior to this patch, every FETCH call would generate a unique queryId with a different size specified. Depending on the workloads, this could lead to a significant bloat in pg_stat_statements, as repeatedly calling a specific cursor would result in a new queryId each time. For example, FETCH 1 c1; and FETCH 2 c1; would produce different queryIds. This patch improves the situation by normalizing the fetch size, so as semantically similar statements generate the same queryId. As a result, statements like the below, which differ syntactically but have the same effect, will now share a single queryId: FETCH FROM c1 FETCH NEXT c1 FETCH 1 c1 In order to do a normalization based on the keyword used in FETCH, FetchStmt is tweaked with a new FetchDirectionKeywords. This matters for "howMany", which could be set to a negative value depending on the direction, and we want to normalize the queries with enough information about the direction keywords provided, including RELATIVE, ABSOLUTE or all the ALL variants. Author: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/CAA5RZ0tA6LbHCg2qSS+KuM850BZC_+ZgHV7Ug6BXw22TNyF+MA@mail.gmail.com |
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| .. | ||
| cleanup.sql | ||
| cursors.sql | ||
| dml.sql | ||
| entry_timestamp.sql | ||
| extended.sql | ||
| level_tracking.sql | ||
| oldextversions.sql | ||
| parallel.sql | ||
| planning.sql | ||
| privileges.sql | ||
| select.sql | ||
| squashing.sql | ||
| user_activity.sql | ||
| utility.sql | ||
| wal.sql | ||