diff options
Diffstat (limited to 'src/backend/access/index/indexam.c')
| -rw-r--r-- | src/backend/access/index/indexam.c | 26 |
1 files changed, 0 insertions, 26 deletions
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c index ae1c87ebadd..0fc9139badb 100644 --- a/src/backend/access/index/indexam.c +++ b/src/backend/access/index/indexam.c @@ -38,32 +38,6 @@ * This file contains the index_ routines which used * to be a scattered collection of stuff in access/genam. * - * - * old comments - * Scans are implemented as follows: - * - * `0' represents an invalid item pointer. - * `-' represents an unknown item pointer. - * `X' represents a known item pointers. - * `+' represents known or invalid item pointers. - * `*' represents any item pointers. - * - * State is represented by a triple of these symbols in the order of - * previous, current, next. Note that the case of reverse scans works - * identically. - * - * State Result - * (1) + + - + 0 0 (if the next item pointer is invalid) - * (2) + X - (otherwise) - * (3) * 0 0 * 0 0 (no change) - * (4) + X 0 X 0 0 (shift) - * (5) * + X + X - (shift, add unknown) - * - * All other states cannot occur. - * - * Note: It would be possible to cache the status of the previous and - * next item pointer using the flags. - * *------------------------------------------------------------------------- */ |