diff options
Diffstat (limited to 'src/include/access/nbtree.h')
| -rw-r--r-- | src/include/access/nbtree.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h index 347d9423ba..9a751ce100 100644 --- a/src/include/access/nbtree.h +++ b/src/include/access/nbtree.h @@ -417,13 +417,18 @@ typedef struct xl_btree_newroot /* * When a new operator class is declared, we require that the user - * supply us with an amproc procedure for determining whether, for - * two keys a and b, a < b, a = b, or a > b. This routine must - * return < 0, 0, > 0, respectively, in these three cases. Since we - * only have one such proc in amproc, it's number 1. + * supply us with an amproc procedure (BTORDER_PROC) for determining + * whether, for two keys a and b, a < b, a = b, or a > b. This routine + * must return < 0, 0, > 0, respectively, in these three cases. (It must + * not return INT_MIN, since we may negate the result before using it.) + * + * To facilitate accelerated sorting, an operator class may choose to + * offer a second procedure (BTSORTSUPPORT_PROC). For full details, see + * src/include/utils/sortsupport.h. */ -#define BTORDER_PROC 1 +#define BTORDER_PROC 1 +#define BTSORTSUPPORT_PROC 2 /* * We need to be able to tell the difference between read and write |