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| author | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2015-03-26 19:12:00 +0200 |
|---|---|---|
| committer | Heikki Linnakangas <heikki.linnakangas@iki.fi> | 2015-03-26 19:12:00 +0200 |
| commit | d04c8ed9044eccebce043143a930617e3998c005 (patch) | |
| tree | e0167be995bb28dab91dfb92f1e18609e91a0d3e /src/backend/access/gist/gist.c | |
| parent | 8fa393a6d739796d9f06a7fba91d7e1d0c354879 (diff) | |
| download | postgresql-d04c8ed9044eccebce043143a930617e3998c005.tar.gz | |
Add support for index-only scans in GiST.
This adds a new GiST opclass method, 'fetch', which is used to reconstruct
the original Datum from the value stored in the index. Also, the 'canreturn'
index AM interface function gains a new 'attno' argument. That makes it
possible to use index-only scans on a multi-column index where some of the
opclasses support index-only scans but some do not.
This patch adds support in the box and point opclasses. Other opclasses
can added later as follow-on patches (btree_gist would be particularly
interesting).
Anastasia Lubennikova, with additional fixes and modifications by me.
Diffstat (limited to 'src/backend/access/gist/gist.c')
| -rw-r--r-- | src/backend/access/gist/gist.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c index db2a452a4a..96b7701633 100644 --- a/src/backend/access/gist/gist.c +++ b/src/backend/access/gist/gist.c @@ -1404,6 +1404,14 @@ initGISTstate(Relation index) else giststate->distanceFn[i].fn_oid = InvalidOid; + /* opclasses are not required to provide a Fetch method */ + if (OidIsValid(index_getprocid(index, i + 1, GIST_FETCH_PROC))) + fmgr_info_copy(&(giststate->fetchFn[i]), + index_getprocinfo(index, i + 1, GIST_FETCH_PROC), + scanCxt); + else + giststate->fetchFn[i].fn_oid = InvalidOid; + /* * If the index column has a specified collation, we should honor that * while doing comparisons. However, we may have a collatable storage |