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| author | Bruce Momjian <bruce@momjian.us> | 2014-03-05 10:43:45 -0500 |
|---|---|---|
| committer | Bruce Momjian <bruce@momjian.us> | 2014-03-05 10:43:45 -0500 |
| commit | 65b96714118d3919195d2dd47e8d2df23718c7ab (patch) | |
| tree | 694351399d547b431b9bd098d762afb41a4a5450 | |
| parent | dd917bb793b27f8c7616f0e64f9a119e8d98eb24 (diff) | |
| download | postgresql-65b96714118d3919195d2dd47e8d2df23718c7ab.tar.gz postgresql-65b96714118d3919195d2dd47e8d2df23718c7ab.zip | |
pg_upgrade: improve C comment about what old/new oids match
| -rw-r--r-- | contrib/pg_upgrade/pg_upgrade.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/contrib/pg_upgrade/pg_upgrade.c b/contrib/pg_upgrade/pg_upgrade.c index b992cadbc50..5e210285060 100644 --- a/contrib/pg_upgrade/pg_upgrade.c +++ b/contrib/pg_upgrade/pg_upgrade.c @@ -15,13 +15,12 @@ * oids are the same between old and new clusters. This is important * because toast oids are stored as toast pointers in user tables. * - * FYI, while pg_class.oid and pg_class.relfilenode are initially the same - * in a cluster, but they can diverge due to CLUSTER, REINDEX, or VACUUM - * FULL. The new cluster will have matching pg_class.oid and - * pg_class.relfilenode values and be based on the old oid value. This can - * cause the old and new pg_class.relfilenode values to differ. In summary, - * old and new pg_class.oid and new pg_class.relfilenode will have the - * same value, and old pg_class.relfilenode might differ. + * While pg_class.oid and pg_class.relfilenode are initially the same + * in a cluster, they can diverge due to CLUSTER, REINDEX, or VACUUM + * FULL. In the new cluster, pg_class.oid and pg_class.relfilenode will + * be the same and will match the old pg_class.oid value. Because of + * this, old/new pg_class.relfilenode values will not match if CLUSTER, + * REINDEX, or VACUUM FULL have been performed in the old cluster. * * We control all assignments of pg_type.oid because these oids are stored * in user composite type values. |