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| author | Tom Lane | 2019-05-22 15:46:57 +0000 |
|---|---|---|
| committer | Tom Lane | 2019-05-22 15:47:02 +0000 |
| commit | 166f69f769c83ef8759d905bf7f1a9aa1d97a340 (patch) | |
| tree | e4e7dcc6de3e1bac0007126c42451fb1e0cef169 /src/include | |
| parent | 728840fe13acff7b03a4b1a813eeb8900ce5e469 (diff) | |
Fix O(N^2) performance issue in pg_publication_tables view.
The original coding of this view relied on a correlated IN sub-query.
Our planner is not very bright about correlated sub-queries, and even
if it were, there's no way for it to know that the output of
pg_get_publication_tables() is duplicate-free, making the de-duplicating
semantics of IN unnecessary. Hence, rewrite as a LATERAL sub-query.
This provides circa 100X speedup for me with a few hundred published
tables (the whole regression database), and things would degrade as
roughly O(published_relations * all_relations) beyond that.
Because the rules.out expected output changes, force a catversion bump.
Ordinarily we might not want to do that post-beta1; but we already know
we'll be doing a catversion bump before beta2 to fix pg_statistic_ext
issues, so it's pretty much free to fix it now instead of waiting for v13.
Per report and fix suggestion from PegoraroF10.
Discussion: https://postgr.es/m/1551385426763-0.post@n3.nabble.com
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/catalog/catversion.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h index c5c06163aa..474d48c8ee 100644 --- a/src/include/catalog/catversion.h +++ b/src/include/catalog/catversion.h @@ -53,6 +53,6 @@ */ /* yyyymmddN */ -#define CATALOG_VERSION_NO 201905141 +#define CATALOG_VERSION_NO 201905221 #endif |