diff options
Diffstat (limited to 'src/include/access/nbtree.h')
| -rw-r--r-- | src/include/access/nbtree.h | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h index 4e20c79ca6e..199fc940267 100644 --- a/src/include/access/nbtree.h +++ b/src/include/access/nbtree.h @@ -472,12 +472,18 @@ typedef BTStackData *BTStack; * items were killed, we re-lock the page to mark them killed, then unlock. * Finally we drop the pin and step to the next page in the appropriate * direction. + * + * If we are doing an index-only scan, we save the entire IndexTuple for each + * matched item, otherwise only its heap TID and offset. The IndexTuples go + * into a separate workspace array; each BTScanPosItem stores its tuple's + * offset within that array. */ typedef struct BTScanPosItem /* what we remember about each match */ { ItemPointerData heapTid; /* TID of referenced heap item */ OffsetNumber indexOffset; /* index item's location within page */ + LocationIndex tupleOffset; /* IndexTuple's offset in workspace, if any */ } BTScanPosItem; typedef struct BTScanPosData @@ -496,6 +502,12 @@ typedef struct BTScanPosData bool moreRight; /* + * If we are doing an index-only scan, nextTupleOffset is the first free + * location in the associated tuple storage workspace. + */ + int nextTupleOffset; + + /* * The items array is always ordered in index order (ie, increasing * indexoffset). When scanning backwards it is convenient to fill the * array back-to-front, so we start at the last slot and fill downwards. @@ -525,6 +537,14 @@ typedef struct BTScanOpaqueData int numKilled; /* number of currently stored items */ /* + * If we are doing an index-only scan, these are the tuple storage + * workspaces for the currPos and markPos respectively. Each is of + * size BLCKSZ, so it can hold as much as a full page's worth of tuples. + */ + char *currTuples; /* tuple storage for currPos */ + char *markTuples; /* tuple storage for markPos */ + + /* * If the marked position is on the same page as current position, we * don't use markPos, but just keep the marked itemIndex in markItemIndex * (all the rest of currPos is valid for the mark position). Hence, to @@ -620,7 +640,7 @@ extern ScanKey _bt_mkscankey_nodata(Relation rel); extern void _bt_freeskey(ScanKey skey); extern void _bt_freestack(BTStack stack); extern void _bt_preprocess_keys(IndexScanDesc scan); -extern bool _bt_checkkeys(IndexScanDesc scan, +extern IndexTuple _bt_checkkeys(IndexScanDesc scan, Page page, OffsetNumber offnum, ScanDirection dir, bool *continuescan); extern void _bt_killitems(IndexScanDesc scan, bool haveLock); |