diff options
Diffstat (limited to 'src/include/access/gist.h')
| -rw-r--r-- | src/include/access/gist.h | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/include/access/gist.h b/src/include/access/gist.h index 73e43e880ab..4994351697c 100644 --- a/src/include/access/gist.h +++ b/src/include/access/gist.h @@ -16,6 +16,7 @@ #ifndef GIST_H #define GIST_H +#include "access/itup.h" #include "access/transam.h" #include "access/xlog.h" #include "access/xlogdefs.h" @@ -35,7 +36,8 @@ #define GIST_EQUAL_PROC 7 #define GIST_DISTANCE_PROC 8 #define GIST_FETCH_PROC 9 -#define GISTNProcs 9 +#define GIST_OPTIONS_PROC 10 +#define GISTNProcs 10 /* * Page opaque data in a GiST index page. @@ -74,6 +76,24 @@ typedef struct GISTPageOpaqueData typedef GISTPageOpaqueData *GISTPageOpaque; /* + * Maximum possible sizes for GiST index tuple and index key. Calculation is + * based on assumption that GiST page should fit at least 4 tuples. In theory, + * GiST index can be functional when page can fit 3 tuples. But that seems + * rather inefficent, so we use a bit conservative estimate. + * + * The maximum size of index key is true for unicolumn index. Therefore, this + * estimation should be used to figure out which maximum size of GiST index key + * makes sense at all. For multicolumn indexes, user might be able to tune + * key size using opclass parameters. + */ +#define GISTMaxIndexTupleSize \ + MAXALIGN_DOWN((BLCKSZ - SizeOfPageHeaderData - sizeof(GISTPageOpaqueData)) / \ + 4 - sizeof(ItemIdData)) + +#define GISTMaxIndexKeySize \ + (GISTMaxIndexTupleSize - MAXALIGN(sizeof(IndexTupleData))) + +/* * The page ID is for the convenience of pg_filedump and similar utilities, * which otherwise would have a hard time telling pages of different index * types apart. It should be the last 2 bytes on the page. This is more or |