Re: Last infomask bit - Mailing list pgsql-patches
| From | Bruce Momjian |
|---|---|
| Subject | Re: Last infomask bit |
| Date | |
| Msg-id | 200701092201.l09M15F17956@momjian.us Whole thread Raw |
| In response to | Last infomask bit (Heikki Linnakangas <heikki@enterprisedb.com>) |
| Responses |
Re: Last infomask bit
|
| List | pgsql-patches |
Patch applied. Thanks. I added a comment about the unused bits in the header file. --------------------------------------------------------------------------- Heikki Linnakangas wrote: > Hi, > > We're running out of infomask bits in the tuple header. I bumped into > this as I tried to apply both the phantom command ids patch, and the HOT > patch simultaneously. They both require one infomask bit, so they > conflicted. > > This has been discussed before; I think the best approach is to use the > extra bits available in t_natts field. Here's a patch that doesn't do > anything interesting in itself, but it renames the t_natts field to > t_infomask2, with 11 bits reserved for the number of attributes and the > other 5 bits available for future use. All references to the old t_natts > field are replaced with a HeapTupleHeaderGetNatts accessor macro. > > I believe it would actually be even better to combine the t_natts and > t_infomask fields to a single 32-bit infomask field. I refrained from > doing that for now because it would've required shifting all the > existing infomask flags. > > Naturally, there's no point applying this before we actually need more > infobits, but it's good to be prepared. > > -- > Heikki Linnakangas > EnterpriseDB http://www.enterprisedb.com [ text/x-patch is unsupported, treating like TEXT/PLAIN ] > Index: src/backend/access/common/heaptuple.c > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/common/heaptuple.c,v > retrieving revision 1.112 > diff -c -r1.112 heaptuple.c > *** src/backend/access/common/heaptuple.c 23 Nov 2006 05:27:18 -0000 1.112 > --- src/backend/access/common/heaptuple.c 5 Jan 2007 13:11:10 -0000 > *************** > *** 295,301 **** > bool > heap_attisnull(HeapTuple tup, int attnum) > { > ! if (attnum > (int) tup->t_data->t_natts) > return true; > > if (attnum > 0) > --- 295,301 ---- > bool > heap_attisnull(HeapTuple tup, int attnum) > { > ! if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data)) > return true; > > if (attnum > 0) > *************** > *** 474,479 **** > --- 474,480 ---- > { > int j = 1; > long off; > + int natts = HeapTupleHeaderGetNatts(tup); > > /* > * need to set cache for some atts > *************** > *** 488,494 **** > > for (; j <= attnum || > /* Can we compute more? We will probably need them */ > ! (j < tup->t_natts && > att[j]->attcacheoff == -1 && > (HeapTupleNoNulls(tuple) || !att_isnull(j, bp)) && > (HeapTupleAllFixed(tuple) || att[j]->attlen > 0)); j++) > --- 489,495 ---- > > for (; j <= attnum || > /* Can we compute more? We will probably need them */ > ! (j < natts && > att[j]->attcacheoff == -1 && > (HeapTupleNoNulls(tuple) || !att_isnull(j, bp)) && > (HeapTupleAllFixed(tuple) || att[j]->attlen > 0)); j++) > *************** > *** 739,745 **** > HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); > HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); > > ! td->t_natts = numberOfAttributes; > td->t_hoff = hoff; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > --- 740,746 ---- > HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); > HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); > > ! HeapTupleHeaderSetNatts(td, numberOfAttributes); > td->t_hoff = hoff; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > *************** > *** 846,852 **** > HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); > HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); > > ! td->t_natts = numberOfAttributes; > td->t_hoff = hoff; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > --- 847,853 ---- > HeapTupleHeaderSetTypeId(td, tupleDescriptor->tdtypeid); > HeapTupleHeaderSetTypMod(td, tupleDescriptor->tdtypmod); > > ! HeapTupleHeaderSetNatts(td, numberOfAttributes); > td->t_hoff = hoff; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > *************** > *** 1035,1041 **** > bits8 *bp = tup->t_bits; /* ptr to null bitmap in tuple */ > bool slow = false; /* can we use/set attcacheoff? */ > > ! natts = tup->t_natts; > > /* > * In inheritance situations, it is possible that the given tuple actually > --- 1036,1042 ---- > bits8 *bp = tup->t_bits; /* ptr to null bitmap in tuple */ > bool slow = false; /* can we use/set attcacheoff? */ > > ! natts = HeapTupleHeaderGetNatts(tup); > > /* > * In inheritance situations, it is possible that the given tuple actually > *************** > *** 1128,1134 **** > bits8 *bp = tup->t_bits; /* ptr to null bitmap in tuple */ > bool slow = false; /* can we use/set attcacheoff? */ > > ! natts = tup->t_natts; > > /* > * In inheritance situations, it is possible that the given tuple actually > --- 1129,1135 ---- > bits8 *bp = tup->t_bits; /* ptr to null bitmap in tuple */ > bool slow = false; /* can we use/set attcacheoff? */ > > ! natts = HeapTupleHeaderGetNatts(tup); > > /* > * In inheritance situations, it is possible that the given tuple actually > *************** > *** 1335,1341 **** > * than the tupdesc.) > */ > tup = tuple->t_data; > ! if (attnum > tup->t_natts) > { > *isnull = true; > return (Datum) 0; > --- 1336,1342 ---- > * than the tupdesc.) > */ > tup = tuple->t_data; > ! if (attnum > HeapTupleHeaderGetNatts(tup)) > { > *isnull = true; > return (Datum) 0; > *************** > *** 1401,1407 **** > /* > * load up any slots available from physical tuple > */ > ! attnum = tuple->t_data->t_natts; > attnum = Min(attnum, tdesc_natts); > > slot_deform_tuple(slot, attnum); > --- 1402,1408 ---- > /* > * load up any slots available from physical tuple > */ > ! attnum = HeapTupleHeaderGetNatts(tuple->t_data); > attnum = Min(attnum, tdesc_natts); > > slot_deform_tuple(slot, attnum); > *************** > *** 1448,1454 **** > /* > * load up any slots available from physical tuple > */ > ! attno = tuple->t_data->t_natts; > attno = Min(attno, attnum); > > slot_deform_tuple(slot, attno); > --- 1449,1455 ---- > /* > * load up any slots available from physical tuple > */ > ! attno = HeapTupleHeaderGetNatts(tuple->t_data); > attno = Min(attno, attnum); > > slot_deform_tuple(slot, attno); > *************** > *** 1601,1607 **** > * And fill in the information. > */ > tuple->t_len = len; > ! tuple->t_natts = numberOfAttributes; > tuple->t_hoff = hoff + MINIMAL_TUPLE_OFFSET; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > --- 1602,1608 ---- > * And fill in the information. > */ > tuple->t_len = len; > ! HeapTupleHeaderSetNatts(tuple, numberOfAttributes); > tuple->t_hoff = hoff + MINIMAL_TUPLE_OFFSET; > > if (tupleDescriptor->tdhasoid) /* else leave infomask = 0 */ > *************** > *** 1663,1669 **** > result->t_tableOid = InvalidOid; > result->t_data = (HeapTupleHeader) ((char *) result + HEAPTUPLESIZE); > memcpy((char *) result->t_data + MINIMAL_TUPLE_OFFSET, mtup, mtup->t_len); > ! memset(result->t_data, 0, offsetof(HeapTupleHeaderData, t_natts)); > return result; > } > > --- 1664,1670 ---- > result->t_tableOid = InvalidOid; > result->t_data = (HeapTupleHeader) ((char *) result + HEAPTUPLESIZE); > memcpy((char *) result->t_data + MINIMAL_TUPLE_OFFSET, mtup, mtup->t_len); > ! memset(result->t_data, 0, offsetof(HeapTupleHeaderData, t_infomask2)); > return result; > } > > *************** > *** 1729,1735 **** > > /* we don't bother to fill the Datum fields */ > > ! td->t_natts = natts; > td->t_hoff = hoff; > > if (withoid) /* else leave infomask = 0 */ > --- 1730,1736 ---- > > /* we don't bother to fill the Datum fields */ > > ! HeapTupleHeaderSetNatts(td, natts); > td->t_hoff = hoff; > > if (withoid) /* else leave infomask = 0 */ > Index: src/backend/access/heap/heapam.c > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/heap/heapam.c,v > retrieving revision 1.222 > diff -c -r1.222 heapam.c > *** src/backend/access/heap/heapam.c 17 Nov 2006 18:00:14 -0000 1.222 > --- src/backend/access/heap/heapam.c 5 Jan 2007 13:13:30 -0000 > *************** > *** 1455,1461 **** > rdata[0].buffer = InvalidBuffer; > rdata[0].next = &(rdata[1]); > > ! xlhdr.t_natts = heaptup->t_data->t_natts; > xlhdr.t_infomask = heaptup->t_data->t_infomask; > xlhdr.t_hoff = heaptup->t_data->t_hoff; > > --- 1455,1461 ---- > rdata[0].buffer = InvalidBuffer; > rdata[0].next = &(rdata[1]); > > ! xlhdr.t_infomask2 = heaptup->t_data->t_infomask2; > xlhdr.t_infomask = heaptup->t_data->t_infomask; > xlhdr.t_hoff = heaptup->t_data->t_hoff; > > *************** > *** 3204,3210 **** > rdata[1].buffer_std = true; > rdata[1].next = &(rdata[2]); > > ! xlhdr.hdr.t_natts = newtup->t_data->t_natts; > xlhdr.hdr.t_infomask = newtup->t_data->t_infomask; > xlhdr.hdr.t_hoff = newtup->t_data->t_hoff; > if (move) /* remember xmax & xmin */ > --- 3204,3210 ---- > rdata[1].buffer_std = true; > rdata[1].next = &(rdata[2]); > > ! xlhdr.hdr.t_infomask2 = newtup->t_data->t_infomask2; > xlhdr.hdr.t_infomask = newtup->t_data->t_infomask; > xlhdr.hdr.t_hoff = newtup->t_data->t_hoff; > if (move) /* remember xmax & xmin */ > *************** > *** 3503,3509 **** > (char *) xlrec + SizeOfHeapInsert + SizeOfHeapHeader, > newlen); > newlen += offsetof(HeapTupleHeaderData, t_bits); > ! htup->t_natts = xlhdr.t_natts; > htup->t_infomask = xlhdr.t_infomask; > htup->t_hoff = xlhdr.t_hoff; > HeapTupleHeaderSetXmin(htup, record->xl_xid); > --- 3503,3509 ---- > (char *) xlrec + SizeOfHeapInsert + SizeOfHeapHeader, > newlen); > newlen += offsetof(HeapTupleHeaderData, t_bits); > ! htup->t_infomask2 = xlhdr.t_infomask2; > htup->t_infomask = xlhdr.t_infomask; > htup->t_hoff = xlhdr.t_hoff; > HeapTupleHeaderSetXmin(htup, record->xl_xid); > *************** > *** 3666,3672 **** > (char *) xlrec + hsize, > newlen); > newlen += offsetof(HeapTupleHeaderData, t_bits); > ! htup->t_natts = xlhdr.t_natts; > htup->t_infomask = xlhdr.t_infomask; > htup->t_hoff = xlhdr.t_hoff; > > --- 3666,3672 ---- > (char *) xlrec + hsize, > newlen); > newlen += offsetof(HeapTupleHeaderData, t_bits); > ! htup->t_infomask2 = xlhdr.t_infomask2; > htup->t_infomask = xlhdr.t_infomask; > htup->t_hoff = xlhdr.t_hoff; > > Index: src/backend/executor/spi.c > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/executor/spi.c,v > retrieving revision 1.165.2.2 > diff -c -r1.165.2.2 spi.c > *** src/backend/executor/spi.c 26 Dec 2006 16:56:22 -0000 1.165.2.2 > --- src/backend/executor/spi.c 5 Jan 2007 13:16:42 -0000 > *************** > *** 651,657 **** > > SPI_result = 0; > > ! if (fnumber > tuple->t_data->t_natts || fnumber == 0 || > fnumber <= FirstLowInvalidHeapAttributeNumber) > { > SPI_result = SPI_ERROR_NOATTRIBUTE; > --- 651,657 ---- > > SPI_result = 0; > > ! if (fnumber > HeapTupleHeaderGetNatts(tuple->t_data) || fnumber == 0 || > fnumber <= FirstLowInvalidHeapAttributeNumber) > { > SPI_result = SPI_ERROR_NOATTRIBUTE; > *************** > *** 692,698 **** > { > SPI_result = 0; > > ! if (fnumber > tuple->t_data->t_natts || fnumber == 0 || > fnumber <= FirstLowInvalidHeapAttributeNumber) > { > SPI_result = SPI_ERROR_NOATTRIBUTE; > --- 692,698 ---- > { > SPI_result = 0; > > ! if (fnumber > HeapTupleHeaderGetNatts(tuple->t_data) || fnumber == 0 || > fnumber <= FirstLowInvalidHeapAttributeNumber) > { > SPI_result = SPI_ERROR_NOATTRIBUTE; > Index: src/include/access/heapam.h > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/heapam.h,v > retrieving revision 1.117 > diff -c -r1.117 heapam.h > *** src/include/access/heapam.h 5 Nov 2006 22:42:10 -0000 1.117 > --- src/include/access/heapam.h 5 Jan 2007 13:15:10 -0000 > *************** > *** 98,104 **** > ( \ > ((attnum) > 0) ? \ > ( \ > ! ((attnum) > (int) (tup)->t_data->t_natts) ? \ > ( \ > (((isnull) != NULL) ? (*(isnull) = true) : (dummyret)NULL), \ > (Datum)NULL \ > --- 98,104 ---- > ( \ > ((attnum) > 0) ? \ > ( \ > ! ((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \ > ( \ > (((isnull) != NULL) ? (*(isnull) = true) : (dummyret)NULL), \ > (Datum)NULL \ > Index: src/include/access/htup.h > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/htup.h,v > retrieving revision 1.87 > diff -c -r1.87 htup.h > *** src/include/access/htup.h 5 Nov 2006 22:42:10 -0000 1.87 > --- src/include/access/htup.h 5 Jan 2007 13:08:41 -0000 > *************** > *** 139,145 **** > > /* Fields below here must match MinimalTupleData! */ > > ! int16 t_natts; /* number of attributes */ > > uint16 t_infomask; /* various flag bits, see below */ > > --- 139,145 ---- > > /* Fields below here must match MinimalTupleData! */ > > ! uint16 t_infomask2; /* number of attributes + various flags */ > > uint16 t_infomask; /* various flag bits, see below */ > > *************** > *** 182,187 **** > --- 182,195 ---- > > #define HEAP_XACT_MASK 0xFFC0 /* visibility-related bits */ > > + /* information stored in t_infomask2, and accessor macros */ > + #define HEAP_NATTS_MASK 0X7FF /* 11 bits for number of attributes */ > + > + #define HeapTupleHeaderGetNatts(tup) ((tup)->t_infomask2 & HEAP_NATTS_MASK) > + #define HeapTupleHeaderSetNatts(tup, natts) \ > + ( \ > + (tup)->t_infomask2 = ((tup)->t_infomask2 & ~HEAP_NATTS_MASK) | (natts) \ > + ) > > /* > * HeapTupleHeader accessor macros > *************** > *** 367,374 **** > * and thereby prevent accidental use of the nonexistent fields. > * > * MinimalTupleData contains a length word, some padding, and fields matching > ! * HeapTupleHeaderData beginning with t_natts. The padding is chosen so that > ! * offsetof(t_natts) is the same modulo MAXIMUM_ALIGNOF in both structs. > * This makes data alignment rules equivalent in both cases. > * > * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is > --- 375,382 ---- > * and thereby prevent accidental use of the nonexistent fields. > * > * MinimalTupleData contains a length word, some padding, and fields matching > ! * HeapTupleHeaderData beginning with t_infomask2. The padding is chosen so that > ! * offsetof(t_infomask2) is the same modulo MAXIMUM_ALIGNOF in both structs. > * This makes data alignment rules equivalent in both cases. > * > * When a minimal tuple is accessed via a HeapTupleData pointer, t_data is > *************** > *** 380,388 **** > * the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however. > */ > #define MINIMAL_TUPLE_OFFSET \ > ! ((offsetof(HeapTupleHeaderData, t_natts) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF) > #define MINIMAL_TUPLE_PADDING \ > ! ((offsetof(HeapTupleHeaderData, t_natts) - sizeof(uint32)) % MAXIMUM_ALIGNOF) > > typedef struct MinimalTupleData > { > --- 388,396 ---- > * the MINIMAL_TUPLE_OFFSET distance. t_len does not include that, however. > */ > #define MINIMAL_TUPLE_OFFSET \ > ! ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) / MAXIMUM_ALIGNOF * MAXIMUM_ALIGNOF) > #define MINIMAL_TUPLE_PADDING \ > ! ((offsetof(HeapTupleHeaderData, t_infomask2) - sizeof(uint32)) % MAXIMUM_ALIGNOF) > > typedef struct MinimalTupleData > { > *************** > *** 392,398 **** > > /* Fields below here must match HeapTupleHeaderData! */ > > ! int16 t_natts; /* number of attributes */ > > uint16 t_infomask; /* various flag bits, see below */ > > --- 400,406 ---- > > /* Fields below here must match HeapTupleHeaderData! */ > > ! uint16 t_infomask2; /* number of attributes + various flags */ > > uint16 t_infomask; /* various flag bits, see below */ > > *************** > *** 552,558 **** > */ > typedef struct xl_heap_header > { > ! int16 t_natts; > uint16 t_infomask; > uint8 t_hoff; > } xl_heap_header; > --- 560,566 ---- > */ > typedef struct xl_heap_header > { > ! uint16 t_infomask2; > uint16 t_infomask; > uint8 t_hoff; > } xl_heap_header; > Index: src/pl/plpgsql/src/pl_exec.c > =================================================================== > RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/pl/plpgsql/src/pl_exec.c,v > retrieving revision 1.180 > diff -c -r1.180 pl_exec.c > *** src/pl/plpgsql/src/pl_exec.c 4 Oct 2006 00:30:13 -0000 1.180 > --- src/pl/plpgsql/src/pl_exec.c 5 Jan 2007 13:19:14 -0000 > *************** > *** 4092,4098 **** > * Row is a bit more complicated in that we assign the individual > * attributes of the tuple to the variables the row points to. > * > ! * NOTE: this code used to demand row->nfields == tup->t_data->t_natts, > * but that's wrong. The tuple might have more fields than we expected if > * it's from an inheritance-child table of the current table, or it might > * have fewer if the table has had columns added by ALTER TABLE. Ignore > --- 4092,4098 ---- > * Row is a bit more complicated in that we assign the individual > * attributes of the tuple to the variables the row points to. > * > ! * NOTE: this code used to demand row->nfields == HeapTupleHeaderGetNatts(tup->t_data, > * but that's wrong. The tuple might have more fields than we expected if > * it's from an inheritance-child table of the current table, or it might > * have fewer if the table has had columns added by ALTER TABLE. Ignore > *************** > *** 4110,4116 **** > int anum; > > if (HeapTupleIsValid(tup)) > ! t_natts = tup->t_data->t_natts; > else > t_natts = 0; > > --- 4110,4116 ---- > int anum; > > if (HeapTupleIsValid(tup)) > ! t_natts = HeapTupleHeaderGetNatts(tup->t_data); > else > t_natts = 0; > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend -- Bruce Momjian bruce@momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
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