diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/access/heap/tuptoaster.c | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c index 1a3c01bcac9..2d09b773614 100644 --- a/src/backend/access/heap/tuptoaster.c +++ b/src/backend/access/heap/tuptoaster.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.74 2007/04/06 04:21:41 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.75 2007/09/26 23:29:10 tgl Exp $ * * * INTERFACE ROUTINES @@ -525,11 +525,16 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, /* * We took care of UPDATE above, so any external value we find * still in the tuple must be someone else's we cannot reuse. - * Expand it to plain (and, probably, toast it again below). + * Fetch it back (without decompression, unless we are forcing + * PLAIN storage). If necessary, we'll push it out as a new + * external value below. */ if (VARATT_IS_EXTERNAL(new_value)) { - new_value = heap_tuple_untoast_attr(new_value); + if (att[i]->attstorage == 'p') + new_value = heap_tuple_untoast_attr(new_value); + else + new_value = heap_tuple_fetch_attr(new_value); toast_values[i] = PointerGetDatum(new_value); toast_free[i] = true; need_change = true; @@ -590,7 +595,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) - continue; + continue; /* can't happen, toast_action would be 'p' */ if (VARATT_IS_COMPRESSED(toast_values[i])) continue; if (att[i]->attstorage != 'x') @@ -654,7 +659,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) - continue; + continue; /* can't happen, toast_action would be 'p' */ if (att[i]->attstorage != 'x' && att[i]->attstorage != 'e') continue; if (toast_sizes[i] > biggest_size) @@ -703,7 +708,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, if (toast_action[i] != ' ') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) - continue; + continue; /* can't happen, toast_action would be 'p' */ if (VARATT_IS_COMPRESSED(toast_values[i])) continue; if (att[i]->attstorage != 'm') @@ -766,7 +771,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup, if (toast_action[i] == 'p') continue; if (VARATT_IS_EXTERNAL(toast_values[i])) - continue; + continue; /* can't happen, toast_action would be 'p' */ if (att[i]->attstorage != 'm') continue; if (toast_sizes[i] > biggest_size) @@ -1025,6 +1030,12 @@ toast_compress_datum(Datum value) Assert(!VARATT_IS_EXTERNAL(value)); Assert(!VARATT_IS_COMPRESSED(value)); + /* + * No point in wasting a palloc cycle if value is too short for compression + */ + if (valsize < PGLZ_strategy_default->min_input_size) + return PointerGetDatum(NULL); + tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize)); if (pglz_compress(VARDATA_ANY(value), valsize, (PGLZ_Header *) tmp, PGLZ_strategy_default) && @@ -1438,10 +1449,18 @@ toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset, int32 length) int32 chcpystrt; int32 chcpyend; + Assert(VARATT_IS_EXTERNAL(attr)); + /* Must copy to access aligned fields */ memcpy(&toast_pointer, VARDATA_SHORT(attr), sizeof(struct varatt_external)); + /* + * It's nonsense to fetch slices of a compressed datum -- this isn't lo_* + * we can't return a compressed datum which is meaningful to toast later + */ + Assert(!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer)); + attrsize = toast_pointer.va_extsize; totalchunks = ((attrsize - 1) / TOAST_MAX_CHUNK_SIZE) + 1; |