|
8 | 8 | * |
9 | 9 | * |
10 | 10 | * IDENTIFICATION |
11 | | - * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.74 2007/04/06 04:21:41 tgl Exp $ |
| 11 | + * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.75 2007/09/26 23:29:10 tgl Exp $ |
12 | 12 | * |
13 | 13 | * |
14 | 14 | * INTERFACE ROUTINES |
@@ -525,11 +525,16 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, |
525 | 525 | /* |
526 | 526 | * We took care of UPDATE above, so any external value we find |
527 | 527 | * still in the tuple must be someone else's we cannot reuse. |
528 | | - * Expand it to plain (and, probably, toast it again below). |
| 528 | + * Fetch it back (without decompression, unless we are forcing |
| 529 | + * PLAIN storage). If necessary, we'll push it out as a new |
| 530 | + * external value below. |
529 | 531 | */ |
530 | 532 | if (VARATT_IS_EXTERNAL(new_value)) |
531 | 533 | { |
532 | | -new_value=heap_tuple_untoast_attr(new_value); |
| 534 | +if (att[i]->attstorage=='p') |
| 535 | +new_value=heap_tuple_untoast_attr(new_value); |
| 536 | +else |
| 537 | +new_value=heap_tuple_fetch_attr(new_value); |
533 | 538 | toast_values[i]=PointerGetDatum(new_value); |
534 | 539 | toast_free[i]= true; |
535 | 540 | need_change= true; |
@@ -590,7 +595,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, |
590 | 595 | if (toast_action[i]!=' ') |
591 | 596 | continue; |
592 | 597 | if (VARATT_IS_EXTERNAL(toast_values[i])) |
593 | | -continue; |
| 598 | +continue;/* can't happen, toast_action would be 'p' */ |
594 | 599 | if (VARATT_IS_COMPRESSED(toast_values[i])) |
595 | 600 | continue; |
596 | 601 | if (att[i]->attstorage!='x') |
@@ -654,7 +659,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, |
654 | 659 | if (toast_action[i]=='p') |
655 | 660 | continue; |
656 | 661 | if (VARATT_IS_EXTERNAL(toast_values[i])) |
657 | | -continue; |
| 662 | +continue;/* can't happen, toast_action would be 'p' */ |
658 | 663 | if (att[i]->attstorage!='x'&&att[i]->attstorage!='e') |
659 | 664 | continue; |
660 | 665 | if (toast_sizes[i]>biggest_size) |
@@ -703,7 +708,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, |
703 | 708 | if (toast_action[i]!=' ') |
704 | 709 | continue; |
705 | 710 | if (VARATT_IS_EXTERNAL(toast_values[i])) |
706 | | -continue; |
| 711 | +continue;/* can't happen, toast_action would be 'p' */ |
707 | 712 | if (VARATT_IS_COMPRESSED(toast_values[i])) |
708 | 713 | continue; |
709 | 714 | if (att[i]->attstorage!='m') |
@@ -766,7 +771,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, |
766 | 771 | if (toast_action[i]=='p') |
767 | 772 | continue; |
768 | 773 | if (VARATT_IS_EXTERNAL(toast_values[i])) |
769 | | -continue; |
| 774 | +continue;/* can't happen, toast_action would be 'p' */ |
770 | 775 | if (att[i]->attstorage!='m') |
771 | 776 | continue; |
772 | 777 | if (toast_sizes[i]>biggest_size) |
@@ -1025,6 +1030,12 @@ toast_compress_datum(Datum value) |
1025 | 1030 | Assert(!VARATT_IS_EXTERNAL(value)); |
1026 | 1031 | Assert(!VARATT_IS_COMPRESSED(value)); |
1027 | 1032 |
|
| 1033 | +/* |
| 1034 | + * No point in wasting a palloc cycle if value is too short for compression |
| 1035 | + */ |
| 1036 | +if (valsize<PGLZ_strategy_default->min_input_size) |
| 1037 | +returnPointerGetDatum(NULL); |
| 1038 | + |
1028 | 1039 | tmp= (structvarlena*)palloc(PGLZ_MAX_OUTPUT(valsize)); |
1029 | 1040 | if (pglz_compress(VARDATA_ANY(value),valsize, |
1030 | 1041 | (PGLZ_Header*)tmp,PGLZ_strategy_default)&& |
@@ -1438,10 +1449,18 @@ toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset, int32 length) |
1438 | 1449 | int32chcpystrt; |
1439 | 1450 | int32chcpyend; |
1440 | 1451 |
|
| 1452 | +Assert(VARATT_IS_EXTERNAL(attr)); |
| 1453 | + |
1441 | 1454 | /* Must copy to access aligned fields */ |
1442 | 1455 | memcpy(&toast_pointer,VARDATA_SHORT(attr), |
1443 | 1456 | sizeof(structvaratt_external)); |
1444 | 1457 |
|
| 1458 | +/* |
| 1459 | + * It's nonsense to fetch slices of a compressed datum -- this isn't lo_* |
| 1460 | + * we can't return a compressed datum which is meaningful to toast later |
| 1461 | + */ |
| 1462 | +Assert(!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer)); |
| 1463 | + |
1445 | 1464 | attrsize=toast_pointer.va_extsize; |
1446 | 1465 | totalchunks= ((attrsize-1) /TOAST_MAX_CHUNK_SIZE)+1; |
1447 | 1466 |
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