diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c index e39b977..bbdee4f 100644 --- a/src/backend/access/common/heaptuple.c +++ b/src/backend/access/common/heaptuple.c @@ -60,7 +60,11 @@ #include "access/sysattr.h" #include "access/tuptoaster.h" #include "executor/tuptable.h" +#include "utils/datum.h" +#include "utils/pg_lzcompress.h" +/* guc variable for EWT compression ratio*/ +int wal_update_compression_ratio = 25; /* Does att's datatype allow packing into the 1-byte-header varlena format? */ #define ATT_IS_PACKABLE(att) \ @@ -617,6 +621,119 @@ heap_copytuple_with_tuple(HeapTuple src, HeapTuple dest) memcpy((char *) dest->t_data, (char *) src->t_data, src->t_len); } + +/* ---------------- + * heap_delta_encode + * + * Calculate the delta between two tuples, using pglz. The result is + * stored in *encdata. *encdata must point to a PGLZ_header buffer, with at + * least PGLZ_MAX_OUTPUT(newtup->t_len) bytes. + * ---------------- + */ +bool +heap_delta_encode(TupleDesc tupleDesc, HeapTuple oldtup, HeapTuple newtup, + char *encdata) +{ + HeapTupleHeader tup = oldtup->t_data; + Form_pg_attribute *att = tupleDesc->attrs; + bool hasnulls = HeapTupleHasNulls(oldtup); + bits8 *bp = oldtup->t_data->t_bits; /* ptr to null bitmap in tuple */ + bool slow = false; /* can we use/set attcacheoff? */ + char *tp; /* ptr to tuple data */ + long off; /* offset in tuple data */ + int natts; + int32 *offsets; + int noffsets; + int attnum; + PGLZ_Strategy strategy; + + /* + * Loop through all attributes, if the attribute is modified by the update + * operation, store the [Offset,Length] reffering old tuple version till + * the last unchanged column in the EWT as History Reference, else store + * the [Length,Data] from new tuple version as New Data. + */ + natts = HeapTupleHeaderGetNatts(oldtup->t_data); + + offsets = palloc(natts * sizeof(int32)); + + noffsets = 0; + + /* copied from heap_deform_tuple */ + tp = (char *) tup + tup->t_hoff; + off = 0; + for (attnum = 0; attnum < natts; attnum++) + { + Form_pg_attribute thisatt = att[attnum]; + + if (hasnulls && att_isnull(attnum, bp)) + { + slow = true; /* can't use attcacheoff anymore */ + continue; + } + + if (!slow && thisatt->attcacheoff >= 0) + off = thisatt->attcacheoff; + else if (thisatt->attlen == -1) + { + /* + * We can only cache the offset for a varlena attribute if the + * offset is already suitably aligned, so that there would be no + * pad bytes in any case: then the offset will be valid for either + * an aligned or unaligned value. + */ + if (!slow && + off == att_align_nominal(off, thisatt->attalign)) + thisatt->attcacheoff = off; + else + { + off = att_align_pointer(off, thisatt->attalign, -1, + tp + off); + slow = true; + } + } + else + { + /* not varlena, so safe to use att_align_nominal */ + off = att_align_nominal(off, thisatt->attalign); + + if (!slow) + thisatt->attcacheoff = off; + } + + off = att_addlength_pointer(off, thisatt->attlen, tp + off); + + if (thisatt->attlen <= 0) + slow = true; /* can't use attcacheoff anymore */ + + offsets[noffsets++] = off; + } + + strategy = *PGLZ_strategy_always; + strategy.min_comp_rate = wal_update_compression_ratio; + + return pglz_compress_with_history((char *) oldtup->t_data, oldtup->t_len, + (char *) newtup->t_data, newtup->t_len, + offsets, noffsets, (PGLZ_Header *) encdata, + &strategy); +} + +/* ---------------- + * heap_delta_decode + * + * Decode a tuple using delta-encoded WAL tuple and old tuple version. + * ---------------- + */ +void +heap_delta_decode(char *encdata, HeapTuple oldtup, HeapTuple newtup) +{ + return pglz_decompress_with_history((char *) encdata, + newtup->t_data, + &newtup->t_len, + (char *) oldtup->t_data, + oldtup->t_len); +} + /* * heap_form_tuple * construct a tuple from the given values[] and isnull[] arrays, diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 57d47e8..789bbe2 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -70,6 +70,7 @@ #include "utils/snapmgr.h" #include "utils/syscache.h" #include "utils/tqual.h" +#include "utils/pg_lzcompress.h" /* GUC variable */ @@ -5765,6 +5766,16 @@ log_heap_update(Relation reln, Buffer oldbuf, XLogRecPtr recptr; XLogRecData rdata[4]; Page page = BufferGetPage(newbuf); + char *newtupdata; + int newtuplen; + bool compressed = false; + + /* Structure which holds EWT */ + struct + { + PGLZ_Header pglzheader; + char buf[MaxHeapTupleSize]; + } buf; /* Caller should not call me on a non-WAL-logged relation */ Assert(RelationNeedsWAL(reln)); @@ -5774,15 +5785,46 @@ log_heap_update(Relation reln, Buffer oldbuf, else info = XLOG_HEAP_UPDATE; + newtupdata = ((char *) newtup->t_data) + offsetof(HeapTupleHeaderData, t_bits); + newtuplen = newtup->t_len - offsetof(HeapTupleHeaderData, t_bits); + + /* + * EWT can be generated for all new tuple versions created by Update + * operation. Currently we do it when both the old and new tuple versions + * are on same page, because during recovery if the page containing old + * tuple is corrupt, it should not cascade that corruption to other pages. + * Under the general assumption that for long runs most updates tend to + * create new tuple version on same page, there should not be significant + * impact on WAL reduction or performance. + * + * We should not generate EWT when we need to backup the whole bolck in + * WAL as in that case there is no saving by reduced WAL size. + */ + if ((oldbuf == newbuf) && !XLogCheckBufferNeedsBackup(newbuf)) + { + /* Delta-encode the new tuple using the old tuple */ + if (heap_delta_encode(reln->rd_att, oldtup, newtup, (char *) &buf.pglzheader)) + { + compressed = true; + newtupdata = (char *) &buf.pglzheader; + newtuplen = VARSIZE(&buf.pglzheader); + } + } + + xlrec.flags = 0; xlrec.target.node = reln->rd_node; xlrec.target.tid = oldtup->t_self; xlrec.old_xmax = HeapTupleHeaderGetRawXmax(oldtup->t_data); xlrec.old_infobits_set = compute_infobits(oldtup->t_data->t_infomask, oldtup->t_data->t_infomask2); xlrec.new_xmax = HeapTupleHeaderGetRawXmax(newtup->t_data); - xlrec.all_visible_cleared = all_visible_cleared; + if (all_visible_cleared) + xlrec.flags |= XL_HEAP_UPDATE_ALL_VISIBLE_CLEARED; xlrec.newtid = newtup->t_self; - xlrec.new_all_visible_cleared = new_all_visible_cleared; + if (new_all_visible_cleared) + xlrec.flags |= XL_HEAP_UPDATE_NEW_ALL_VISIBLE_CLEARED; + if (compressed) + xlrec.flags |= XL_HEAP_UPDATE_DELTA_ENCODED; rdata[0].data = (char *) &xlrec; rdata[0].len = SizeOfHeapUpdate; @@ -5809,9 +5851,12 @@ log_heap_update(Relation reln, Buffer oldbuf, rdata[2].buffer_std = true; rdata[2].next = &(rdata[3]); - /* PG73FORMAT: write bitmap [+ padding] [+ oid] + data */ - rdata[3].data = (char *) newtup->t_data + offsetof(HeapTupleHeaderData, t_bits); - rdata[3].len = newtup->t_len - offsetof(HeapTupleHeaderData, t_bits); + /* + * PG73FORMAT: write bitmap [+ padding] [+ oid] + data follows ......... + * OR PG93FORMAT [If encoded]: LZ header + Encoded data follows + */ + rdata[3].data = newtupdata; + rdata[3].len = newtuplen; rdata[3].buffer = newbuf; rdata[3].buffer_std = true; rdata[3].next = NULL; @@ -6614,7 +6659,10 @@ heap_xlog_update(XLogRecPtr lsn, XLogRecord *record, bool hot_update) Page page; OffsetNumber offnum; ItemId lp = NULL; + HeapTupleData newtup; + HeapTupleData oldtup; HeapTupleHeader htup; + HeapTupleHeader oldtupdata = NULL; struct { HeapTupleHeaderData hdr; @@ -6629,7 +6677,7 @@ heap_xlog_update(XLogRecPtr lsn, XLogRecord *record, bool hot_update) * The visibility map may need to be fixed even if the heap page is * already up-to-date. */ - if (xlrec->all_visible_cleared) + if (xlrec->flags & XL_HEAP_UPDATE_ALL_VISIBLE_CLEARED) { Relation reln = CreateFakeRelcacheEntry(xlrec->target.node); BlockNumber block = ItemPointerGetBlockNumber(&xlrec->target.tid); @@ -6689,7 +6737,7 @@ heap_xlog_update(XLogRecPtr lsn, XLogRecord *record, bool hot_update) if (PageGetMaxOffsetNumber(page) < offnum || !ItemIdIsNormal(lp)) elog(PANIC, "heap_update_redo: invalid lp"); - htup = (HeapTupleHeader) PageGetItem(page, lp); + oldtupdata = htup = (HeapTupleHeader) PageGetItem(page, lp); htup->t_infomask &= ~(HEAP_XMAX_BITS | HEAP_MOVED); htup->t_infomask2 &= ~HEAP_KEYS_UPDATED; @@ -6707,7 +6755,7 @@ heap_xlog_update(XLogRecPtr lsn, XLogRecord *record, bool hot_update) /* Mark the page as a candidate for pruning */ PageSetPrunable(page, record->xl_xid); - if (xlrec->all_visible_cleared) + if (xlrec->flags & XL_HEAP_UPDATE_ALL_VISIBLE_CLEARED) PageClearAllVisible(page); /* @@ -6732,7 +6780,7 @@ newt:; * The visibility map may need to be fixed even if the heap page is * already up-to-date. */ - if (xlrec->new_all_visible_cleared) + if (xlrec->flags & XL_HEAP_UPDATE_NEW_ALL_VISIBLE_CLEARED) { Relation reln = CreateFakeRelcacheEntry(xlrec->target.node); BlockNumber block = ItemPointerGetBlockNumber(&xlrec->newtid); @@ -6795,10 +6843,32 @@ newsame:; SizeOfHeapHeader); htup = &tbuf.hdr; MemSet((char *) htup, 0, sizeof(HeapTupleHeaderData)); - /* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */ - memcpy((char *) htup + offsetof(HeapTupleHeaderData, t_bits), - (char *) xlrec + hsize, - newlen); + + /* + * If the record is EWT then decode it. + */ + if (xlrec->flags & XL_HEAP_UPDATE_DELTA_ENCODED) + { + /* + * PG93FORMAT: Header + Control byte + history reference (2 - 3)bytes + * + New data (1 byte length + variable data)+ ... + */ + PGLZ_Header *encoded_data = (PGLZ_Header *) (((char *) xlrec) + hsize); + + oldtup.t_data = oldtupdata; + newtup.t_data = htup; + + heap_delta_decode((char *) encoded_data, &oldtup, &newtup); + newlen = newtup.t_len; + } + else + { + /* PG73FORMAT: get bitmap [+ padding] [+ oid] + data */ + memcpy((char *) htup + offsetof(HeapTupleHeaderData, t_bits), + (char *) xlrec + hsize, + newlen); + } + newlen += offsetof(HeapTupleHeaderData, t_bits); htup->t_infomask2 = xlhdr.t_infomask2; htup->t_infomask = xlhdr.t_infomask; @@ -6814,7 +6884,7 @@ newsame:; if (offnum == InvalidOffsetNumber) elog(PANIC, "heap_update_redo: failed to add tuple"); - if (xlrec->new_all_visible_cleared) + if (xlrec->flags & XL_HEAP_UPDATE_NEW_ALL_VISIBLE_CLEARED) PageClearAllVisible(page); freespace = PageGetHeapFreeSpace(page); /* needed to update FSM below */ diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index cf2f6e7..9cd6271 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -1204,6 +1204,28 @@ begin:; } /* + * Determine whether the buffer referenced has to be backed up. Since we don't + * yet have the insert lock, fullPageWrites and forcePageWrites could change + * later, but will not cause any problem because this function is used only to + * identify whether EWT is required for WAL update. + */ +bool +XLogCheckBufferNeedsBackup(Buffer buffer) +{ + bool doPageWrites; + Page page; + + page = BufferGetPage(buffer); + + doPageWrites = XLogCtl->Insert.fullPageWrites || XLogCtl->Insert.forcePageWrites; + + if (doPageWrites && PageGetLSN(page) <= RedoRecPtr) + return true; /* buffer requires backup */ + + return false; /* buffer does not need to be backed up */ +} + +/* * Determine whether the buffer referenced by an XLogRecData item has to * be backed up, and if so fill a BkpBlock struct for it. In any case * save the buffer's LSN at *lsn. diff --git a/src/backend/utils/adt/pg_lzcompress.c b/src/backend/utils/adt/pg_lzcompress.c index 66c64c1..c6ba6af 100644 --- a/src/backend/utils/adt/pg_lzcompress.c +++ b/src/backend/utils/adt/pg_lzcompress.c @@ -373,6 +373,7 @@ do { \ */ static inline int pglz_find_match(PGLZ_HistEntry **hstart, const char *input, const char *end, + const char *historyend, int *lenp, int *offp, int good_match, int good_drop) { PGLZ_HistEntry *hent; @@ -393,7 +394,7 @@ pglz_find_match(PGLZ_HistEntry **hstart, const char *input, const char *end, /* * Stop if the offset does not fit into our tag anymore. */ - thisoff = ip - hp; + thisoff = (historyend ? historyend : ip) - hp; if (thisoff >= 0x0fff) break; @@ -408,12 +409,12 @@ pglz_find_match(PGLZ_HistEntry **hstart, const char *input, const char *end, thislen = 0; if (len >= 16) { - if (memcmp(ip, hp, len) == 0) + if ((historyend == NULL || historyend - hp > len) && memcmp(ip, hp, len) == 0) { thislen = len; ip += len; hp += len; - while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH) + while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH && (historyend == NULL || hp < historyend)) { thislen++; ip++; @@ -423,7 +424,7 @@ pglz_find_match(PGLZ_HistEntry **hstart, const char *input, const char *end, } else { - while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH) + while (ip < end && *ip == *hp && thislen < PGLZ_MAX_MATCH && (historyend == NULL || hp < historyend)) { thislen++; ip++; @@ -588,7 +589,7 @@ pglz_compress(const char *source, int32 slen, PGLZ_Header *dest, /* * Try to find a match in the history */ - if (pglz_find_match(hist_start, dp, dend, &match_len, + if (pglz_find_match(hist_start, dp, dend, NULL, &match_len, &match_off, good_match, good_drop)) { /* @@ -637,6 +638,176 @@ pglz_compress(const char *source, int32 slen, PGLZ_Header *dest, return true; } +/* + * Like pglz_compress, but performs delta encoding rather than compression. + * The back references are offsets from the end of history data, rather + * than current output position. 'hoffsets' is an array of offsets in the + * history to consider. We could scan the whole history string for possible + * matches, but if the caller has some information on which offsets are + * likely to be interesting (attribute boundaries, when encoding tuples, for + * example), this is a lot faster. + */ +bool +pglz_compress_with_history(const char *source, int32 slen, const char *history, + int32 hlen, + int32 *hoffsets, + int32 nhoffsets, + PGLZ_Header *dest, const PGLZ_Strategy *strategy) +{ + unsigned char *bp = ((unsigned char *) dest) + sizeof(PGLZ_Header); + unsigned char *bstart = bp; + int hist_next = 0; + bool hist_recycle = false; + const char *dp = source; + const char *dend = source + slen; + unsigned char ctrl_dummy = 0; + unsigned char *ctrlp = &ctrl_dummy; + unsigned char ctrlb = 0; + unsigned char ctrl = 0; + bool found_match = false; + int32 match_len; + int32 match_off; + int32 good_match; + int32 good_drop; + int32 result_size; + int32 result_max; + int i; + int32 need_rate; + const char *historyend = history + hlen; + + /* + * Our fallback strategy is the default. + */ + if (strategy == NULL) + strategy = PGLZ_strategy_default; + + /* + * If the strategy forbids compression (at all or if source chunk size out + * of range), fail. + */ + if (strategy->match_size_good <= 0 || + slen < strategy->min_input_size || + slen > strategy->max_input_size) + return false; + + /* + * Save the original source size in the header. + */ + dest->rawsize = slen; + + /* + * Limit the match parameters to the supported range. + */ + good_match = strategy->match_size_good; + if (good_match > PGLZ_MAX_MATCH) + good_match = PGLZ_MAX_MATCH; + else if (good_match < 17) + good_match = 17; + + good_drop = strategy->match_size_drop; + if (good_drop < 0) + good_drop = 0; + else if (good_drop > 100) + good_drop = 100; + + need_rate = strategy->min_comp_rate; + if (need_rate < 0) + need_rate = 0; + else if (need_rate > 99) + need_rate = 99; + + /* + * Compute the maximum result size allowed by the strategy, namely the + * input size minus the minimum wanted compression rate. This had better + * be <= slen, else we might overrun the provided output buffer. + */ + if (slen > (INT_MAX / 100)) + { + /* Approximate to avoid overflow */ + result_max = (slen / 100) * (100 - need_rate); + } + else + result_max = (slen * (100 - need_rate)) / 100; + + /* + * Initialize the history lists to empty. We do not need to zero the + * hist_entries[] array; its entries are initialized as they are used. + */ + memset(hist_start, 0, sizeof(hist_start)); + + /* Populate the history hash from the history string */ + for (i = 0; i < nhoffsets; i++) + { + const char *hp = history + hoffsets[i]; + + /* Add this offset to history */ + pglz_hist_add(hist_start, hist_entries, + hist_next, hist_recycle, + hp, historyend); + } + + /* + * Compress the source directly into the output buffer. + */ + dp = source; + while (dp < dend) + { + /* + * If we already exceeded the maximum result size, fail. + * + * We check once per loop; since the loop body could emit as many as 4 + * bytes (a control byte and 3-byte tag), PGLZ_MAX_OUTPUT() had better + * allow 4 slop bytes. + */ + if (bp - bstart >= result_max) + return false; + + /* + * Try to find a match in the history + */ + if (pglz_find_match(hist_start, dp, dend, historyend, &match_len, + &match_off, good_match, good_drop)) + { + /* + * Create the tag and add history entries for all matched + * characters. + */ + pglz_out_tag(ctrlp, ctrlb, ctrl, bp, match_len, match_off); + dp += match_len; + found_match = true; + } + else + { + /* + * No match found. Copy one literal byte. + */ + pglz_out_literal(ctrlp, ctrlb, ctrl, bp, *dp); + dp++; /* Do not do this ++ in the line above! */ + /* The macro would do it four times - Jan. */ + } + } + + if (!found_match) + return false; + + /* + * Write out the last control byte and check that we haven't overrun the + * output size allowed by the strategy. + */ + *ctrlp = ctrlb; + result_size = bp - bstart; + +#ifdef DELTA_DEBUG + elog(LOG, "old %d new %d compressed %d", hlen, slen, result_size); +#endif + + /* + * Success - need only fill in the actual length of the compressed datum. + */ + SET_VARSIZE_COMPRESSED(dest, result_size + sizeof(PGLZ_Header)); + + return true; +} /* ---------- * pglz_decompress - @@ -647,15 +818,39 @@ pglz_compress(const char *source, int32 slen, PGLZ_Header *dest, void pglz_decompress(const PGLZ_Header *source, char *dest) { + pglz_decompress_with_history((char *) source, dest, NULL, NULL, 0); +} + +/* ---------- + * pglz_decompress_with_history - + * + * Decompresses source into dest. + * To decompress, it uses history if provided. + * ---------- + */ +void +pglz_decompress_with_history(const char *source, char *dest, uint32 *destlen, + const char *history, int hlen) +{ + PGLZ_Header src; const unsigned char *sp; const unsigned char *srcend; unsigned char *dp; unsigned char *destend; + const char *historyend = history + hlen; + + /* To avoid the unaligned access of PGLZ_Header */ + memcpy((char *) &src, source, sizeof(PGLZ_Header)); sp = ((const unsigned char *) source) + sizeof(PGLZ_Header); - srcend = ((const unsigned char *) source) + VARSIZE(source); + srcend = ((const unsigned char *) source) + VARSIZE(&src); dp = (unsigned char *) dest; - destend = dp + source->rawsize; + destend = dp + src.rawsize; + + if (destlen) + { + *destlen = src.rawsize; + } while (sp < srcend && dp < destend) { @@ -699,26 +894,38 @@ pglz_decompress(const PGLZ_Header *source, char *dest) break; } - /* - * Now we copy the bytes specified by the tag from OUTPUT to - * OUTPUT. It is dangerous and platform dependent to use - * memcpy() here, because the copied areas could overlap - * extremely! - */ - while (len--) + if (history) + { + /* + * Now we copy the bytes specified by the tag from history + * to OUTPUT. + */ + memcpy(dp, historyend - off, len); + dp += len; + } + else { - *dp = dp[-off]; - dp++; + /* + * Now we copy the bytes specified by the tag from OUTPUT + * to OUTPUT. It is dangerous and platform dependent to + * use memcpy() here, because the copied areas could + * overlap extremely! + */ + while (len--) + { + *dp = dp[-off]; + dp++; + } } } else { /* - * An unset control bit means LITERAL BYTE. So we just copy - * one from INPUT to OUTPUT. + * An unset control bit means LITERAL BYTE. So we just + * copy one from INPUT to OUTPUT. */ - if (dp >= destend) /* check for buffer overrun */ - break; /* do not clobber memory */ + if (dp >= destend) /* check for buffer overrun */ + break; /* do not clobber memory */ *dp++ = *sp++; } diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 6128694..9a37b2d 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -123,6 +123,7 @@ extern int CommitSiblings; extern char *default_tablespace; extern char *temp_tablespaces; extern bool synchronize_seqscans; +extern int wal_update_compression_ratio; extern int ssl_renegotiation_limit; extern char *SSLCipherSuites; @@ -2382,6 +2383,17 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + /* Not for general use */ + {"wal_update_compression_ratio", PGC_USERSET, DEVELOPER_OPTIONS, + gettext_noop("Sets the compression ratio of delta record for wal update"), + NULL, + }, + &wal_update_compression_ratio, + 25, 1, 99, + NULL, NULL, NULL + }, + /* End-of-list marker */ { {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h index 270924a..1825292 100644 --- a/src/include/access/heapam_xlog.h +++ b/src/include/access/heapam_xlog.h @@ -147,13 +147,22 @@ typedef struct xl_heap_update TransactionId old_xmax; /* xmax of the old tuple */ TransactionId new_xmax; /* xmax of the new tuple */ ItemPointerData newtid; /* new inserted tuple id */ - uint8 old_infobits_set; /* infomask bits to set on old tuple */ - bool all_visible_cleared; /* PD_ALL_VISIBLE was cleared */ - bool new_all_visible_cleared; /* same for the page of newtid */ + uint8 old_infobits_set; /* infomask bits to set on old tuple */ + int flags; /* flag bits, see below */ /* NEW TUPLE xl_heap_header AND TUPLE DATA FOLLOWS AT END OF STRUCT */ } xl_heap_update; -#define SizeOfHeapUpdate (offsetof(xl_heap_update, new_all_visible_cleared) + sizeof(bool)) +#define XL_HEAP_UPDATE_ALL_VISIBLE_CLEARED 0x01 /* Indicates as old + * page's all visible + * bit is cleared */ +#define XL_HEAP_UPDATE_NEW_ALL_VISIBLE_CLEARED 0x02 /* Indicates as new + * page's all visible + * bit is cleared */ +#define XL_HEAP_UPDATE_DELTA_ENCODED 0x04 /* Indicates as the + * update operation is + * delta encoded */ + +#define SizeOfHeapUpdate (offsetof(xl_heap_update, flags) + sizeof(int)) /* * This is what we need to know about vacuum page cleanup/redirect diff --git a/src/include/access/htup_details.h b/src/include/access/htup_details.h index cd01ecd..042c8b9 100644 --- a/src/include/access/htup_details.h +++ b/src/include/access/htup_details.h @@ -687,6 +687,11 @@ extern HeapTuple heap_modify_tuple(HeapTuple tuple, extern void heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc, Datum *values, bool *isnull); +extern bool heap_delta_encode(TupleDesc tupleDesc, HeapTuple oldtup, + HeapTuple newtup, char *encdata); +extern void heap_delta_decode (char *encdata, HeapTuple oldtup, + HeapTuple newtup); + /* these three are deprecated versions of the three above: */ extern HeapTuple heap_formtuple(TupleDesc tupleDescriptor, Datum *values, char *nulls); diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 72e3242..15f5d5d 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -261,6 +261,7 @@ typedef struct CheckpointStatsData extern CheckpointStatsData CheckpointStats; extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata); +extern bool XLogCheckBufferNeedsBackup(Buffer buffer); extern void XLogFlush(XLogRecPtr RecPtr); extern bool XLogBackgroundFlush(void); extern bool XLogNeedsFlush(XLogRecPtr RecPtr); diff --git a/src/include/utils/pg_lzcompress.h b/src/include/utils/pg_lzcompress.h index 4af24a3..7a32803 100644 --- a/src/include/utils/pg_lzcompress.h +++ b/src/include/utils/pg_lzcompress.h @@ -107,6 +107,8 @@ extern const PGLZ_Strategy *const PGLZ_strategy_always; */ extern bool pglz_compress(const char *source, int32 slen, PGLZ_Header *dest, const PGLZ_Strategy *strategy); +extern bool pglz_compress_with_history(const char *source, int32 slen, const char *history, int32 hlen, int32 *hoffsets, int32 noffsets, PGLZ_Header *dest, const PGLZ_Strategy *strategy); extern void pglz_decompress(const PGLZ_Header *source, char *dest); +extern void pglz_decompress_with_history(const char *source, char *dest, uint32 *destlen, const char *history, int hlen); #endif /* _PG_LZCOMPRESS_H_ */ diff --git a/src/test/regress/expected/update.out b/src/test/regress/expected/update.out index 71b856f..af46df2 100644 --- a/src/test/regress/expected/update.out +++ b/src/test/regress/expected/update.out @@ -97,3 +97,73 @@ SELECT a, b, char_length(c) FROM update_test; (2 rows) DROP TABLE update_test; +-- +-- Test to update continuos and non continuos columns +-- +DROP TABLE IF EXISTS update_test; +NOTICE: table "update_test" does not exist, skipping +CREATE TABLE update_test ( + bser bigserial, + bln boolean, + ename VARCHAR(25), + perf_f float(8), + grade CHAR, + dept CHAR(5) NOT NULL, + dob DATE, + idnum INT, + addr VARCHAR(30) NOT NULL, + destn CHAR(6), + Gend CHAR, + samba BIGINT, + hgt float, + ctime TIME +); +INSERT INTO update_test VALUES ( + nextval('update_test_bser_seq'::regclass), + TRUE, + 'Test', + 7.169, + 'B', + 'CSD', + '2000-01-01', + 520, + 'road2, + streeeeet2, + city2', + 'dcy2', + 'M', + 12000, + 50.4, + '00:00:00.0' +); +SELECT * from update_test; + bser | bln | ename | perf_f | grade | dept | dob | idnum | addr | destn | gend | samba | hgt | ctime +------+-----+-------+--------+-------+-------+------------+-------+-----------------------------+--------+------+-------+------+---------- + 1 | t | Test | 7.169 | B | CSD | 01-01-2000 | 520 | road2, +| dcy2 | M | 12000 | 50.4 | 00:00:00 + | | | | | | | | streeeeet2,+| | | | | + | | | | | | | | city2 | | | | | +(1 row) + +-- update first column +UPDATE update_test SET bser = bser - 1 + 1; +-- update middle column +UPDATE update_test SET perf_f = 8.9; +-- update last column +UPDATE update_test SET ctime = '00:00:00.1'; +-- update 3 continuos columns +UPDATE update_test SET destn = 'dcy2', samba = 0 WHERE Gend = 'M' and dept = 'CSD'; +-- update two non continuos columns +UPDATE update_test SET destn = 'moved', samba = 0; +UPDATE update_test SET bln = FALSE, hgt = 10.1; +-- update causing some column alignment difference +UPDATE update_test SET ename = 'Tes'; +UPDATE update_test SET dept = 'Test'; +SELECT * from update_test; + bser | bln | ename | perf_f | grade | dept | dob | idnum | addr | destn | gend | samba | hgt | ctime +------+-----+-------+--------+-------+-------+------------+-------+-----------------------------+--------+------+-------+------+------------ + 1 | f | Tes | 8.9 | B | Test | 01-01-2000 | 520 | road2, +| moved | M | 0 | 10.1 | 00:00:00.1 + | | | | | | | | streeeeet2,+| | | | | + | | | | | | | | city2 | | | | | +(1 row) + +DROP TABLE update_test; diff --git a/src/test/regress/sql/update.sql b/src/test/regress/sql/update.sql index a8a028f..1806992 100644 --- a/src/test/regress/sql/update.sql +++ b/src/test/regress/sql/update.sql @@ -59,3 +59,70 @@ UPDATE update_test SET c = repeat('x', 10000) WHERE c = 'car'; SELECT a, b, char_length(c) FROM update_test; DROP TABLE update_test; + + +-- +-- Test to update continuos and non continuos columns +-- + +DROP TABLE IF EXISTS update_test; +CREATE TABLE update_test ( + bser bigserial, + bln boolean, + ename VARCHAR(25), + perf_f float(8), + grade CHAR, + dept CHAR(5) NOT NULL, + dob DATE, + idnum INT, + addr VARCHAR(30) NOT NULL, + destn CHAR(6), + Gend CHAR, + samba BIGINT, + hgt float, + ctime TIME +); + +INSERT INTO update_test VALUES ( + nextval('update_test_bser_seq'::regclass), + TRUE, + 'Test', + 7.169, + 'B', + 'CSD', + '2000-01-01', + 520, + 'road2, + streeeeet2, + city2', + 'dcy2', + 'M', + 12000, + 50.4, + '00:00:00.0' +); + +SELECT * from update_test; + +-- update first column +UPDATE update_test SET bser = bser - 1 + 1; + +-- update middle column +UPDATE update_test SET perf_f = 8.9; + +-- update last column +UPDATE update_test SET ctime = '00:00:00.1'; + +-- update 3 continuos columns +UPDATE update_test SET destn = 'dcy2', samba = 0 WHERE Gend = 'M' and dept = 'CSD'; + +-- update two non continuos columns +UPDATE update_test SET destn = 'moved', samba = 0; +UPDATE update_test SET bln = FALSE, hgt = 10.1; + +-- update causing some column alignment difference +UPDATE update_test SET ename = 'Tes'; +UPDATE update_test SET dept = 'Test'; + +SELECT * from update_test; +DROP TABLE update_test;