diff options
Diffstat (limited to 'src/backend/commands/tablecmds.c')
| -rw-r--r-- | src/backend/commands/tablecmds.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 14e379c0c7..1d599eb8dc 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -3417,12 +3417,13 @@ AlterTableCreateToastTable(Oid relOid, bool silent) /* * Create unique index on chunk_id, chunk_seq. * - * NOTE: the tuple toaster could actually function with a single-column - * index on chunk_id only. However, it couldn't be unique then. We - * want it to be unique as a check against the possibility of - * duplicate TOAST chunk OIDs. Too, the index might be a little more - * efficient this way, since btree isn't all that happy with large - * numbers of equal keys. + * NOTE: the normal TOAST access routines could actually function with + * a single-column index on chunk_id only. However, the slice access + * routines use both columns for faster access to an individual chunk. + * In addition, we want it to be unique as a check against the + * possibility of duplicate TOAST chunk OIDs. The index might also be + * a little more efficient this way, since btree isn't all that happy + * with large numbers of equal keys. */ indexInfo = makeNode(IndexInfo); |