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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2023-12-27 15:55:46 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2023-12-27 15:55:46 -0500 |
| commit | 58054de2d0847c09ef091956f72ae5e9fb9a176e (patch) | |
| tree | 509bfa191ff6a4c455b8b7ac269d9acdcb29d4f3 /src/backend/utils/adt/arrayfuncs.c | |
| parent | 6c361d323b908c0391e05d15afc01957db2e415b (diff) | |
| download | postgresql-58054de2d0847c09ef091956f72ae5e9fb9a176e.tar.gz postgresql-58054de2d0847c09ef091956f72ae5e9fb9a176e.zip | |
Improve the implementation of information_schema._pg_expandarray().
This function was originally coded with a handmade expansion
of the array subscripts. We can do it a little faster and far
more legibly today, by using unnest() WITH ORDINALITY.
While at it, let's apply the rowcount estimation support that exists
for the underlying unnest() function: reduce the default ROWS estimate
to 100 and attach array_unnest_support. I'm not sure that
array_unnest_support can do anything useful today with the call sites
that exist in information_schema, but it can't hurt, and the existing
default rowcount of 1000 is surely much too high for any of these
cases.
The psql.sql regression script is using _pg_expandarray() as a
test case for \sf+. While we could keep doing so, the new one-line
function body makes a poor test case for \sf+ row-numbering, so
switch it to print another information_schema function.
Discussion: https://postgr.es/m/1424303.1703355485@sss.pgh.pa.us
Diffstat (limited to 'src/backend/utils/adt/arrayfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/arrayfuncs.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c index 631012a0f28..e783a24519d 100644 --- a/src/backend/utils/adt/arrayfuncs.c +++ b/src/backend/utils/adt/arrayfuncs.c @@ -6317,6 +6317,9 @@ array_unnest(PG_FUNCTION_ARGS) /* * Planner support function for array_unnest(anyarray) + * + * Note: this is now also used for information_schema._pg_expandarray(), + * which is simply a wrapper around array_unnest(). */ Datum array_unnest_support(PG_FUNCTION_ARGS) |