From 9194b2cb07172e636030b9b4e979b7f2caf7cbc0 Mon Sep 17 00:00:00 2001 From: David Christensen Date: Thu, 24 Feb 2022 11:00:46 -0600 Subject: [PATCH] Add relation/block filtering to pg_waldump This feature allows you to only output records that are targeting a specific RelFileNode and optional BlockNumber within this relation. Currently only applies this filter to the relation's main fork. --- doc/src/sgml/ref/pg_waldump.sgml | 23 ++++++++++ src/bin/pg_waldump/pg_waldump.c | 74 +++++++++++++++++++++++++++++++- 2 files changed, 96 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/ref/pg_waldump.sgml b/doc/src/sgml/ref/pg_waldump.sgml index 5735a161ce..c953703bc8 100644 --- a/doc/src/sgml/ref/pg_waldump.sgml +++ b/doc/src/sgml/ref/pg_waldump.sgml @@ -100,6 +100,29 @@ PostgreSQL documentation + + + + + + Display only records touching the given block. (Requires also + providing the relation via .) + + + + + + + + + + Display only records touching the given relation. The relation is + specified via tablespace oid, database oid, and relfilenode separated + by slashes. + + + + diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c index a6251e1a96..faae547a5c 100644 --- a/src/bin/pg_waldump/pg_waldump.c +++ b/src/bin/pg_waldump/pg_waldump.c @@ -55,6 +55,10 @@ typedef struct XLogDumpConfig bool filter_by_rmgr_enabled; TransactionId filter_by_xid; bool filter_by_xid_enabled; + RelFileNode filter_by_relation; + bool filter_by_relation_enabled; + BlockNumber filter_by_relation_block; + bool filter_by_relation_block_enabled; } XLogDumpConfig; typedef struct Stats @@ -394,6 +398,34 @@ WALDumpReadPage(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen, return count; } +/* + * Boolean to return whether the given WAL record matches a specific relation and optional block + */ +static bool +XLogRecordMatchesRelationBlock(XLogReaderState *record, RelFileNode matchRnode, BlockNumber matchBlock) +{ + RelFileNode rnode; + ForkNumber forknum; + BlockNumber blk; + int block_id; + + for (block_id = 0; block_id <= record->max_block_id; block_id++) + { + if (!XLogRecHasBlockRef(record, block_id)) + continue; + + XLogRecGetBlockTag(record, block_id, &rnode, &forknum, &blk); + + if (forknum == MAIN_FORKNUM && + matchRnode.spcNode == rnode.spcNode && + matchRnode.dbNode == rnode.dbNode && + matchRnode.relNode == rnode.relNode && + (matchBlock == InvalidBlockNumber || matchBlock == blk)) + return true; + } + return false; +} + /* * Calculate the size of a record, split into !FPI and FPI parts. */ @@ -767,6 +799,8 @@ usage(void) printf(_(" -b, --bkp-details output detailed information about backup blocks\n")); printf(_(" -e, --end=RECPTR stop reading at WAL location RECPTR\n")); printf(_(" -f, --follow keep retrying after reaching end of WAL\n")); + printf(_(" -k, --block=N only show records matching a given relation block (requires -l)\n")); + printf(_(" -l, --relation=N/N/N only show records that touch a specific relation\n")); printf(_(" -n, --limit=N number of records to display\n")); printf(_(" -p, --path=PATH directory in which to find log segment files or a\n" " directory with a ./pg_wal that contains such files\n" @@ -802,12 +836,14 @@ main(int argc, char **argv) static struct option long_options[] = { {"bkp-details", no_argument, NULL, 'b'}, + {"block", required_argument, NULL, 'k'}, {"end", required_argument, NULL, 'e'}, {"follow", no_argument, NULL, 'f'}, {"help", no_argument, NULL, '?'}, {"limit", required_argument, NULL, 'n'}, {"path", required_argument, NULL, 'p'}, {"quiet", no_argument, NULL, 'q'}, + {"relation", required_argument, NULL, 'l'}, {"rmgr", required_argument, NULL, 'r'}, {"start", required_argument, NULL, 's'}, {"timeline", required_argument, NULL, 't'}, @@ -860,6 +896,8 @@ main(int argc, char **argv) config.filter_by_rmgr_enabled = false; config.filter_by_xid = InvalidTransactionId; config.filter_by_xid_enabled = false; + config.filter_by_relation_enabled = false; + config.filter_by_relation_block_enabled = false; config.stats = false; config.stats_per_record = false; @@ -872,7 +910,7 @@ main(int argc, char **argv) goto bad_argument; } - while ((option = getopt_long(argc, argv, "be:fn:p:qr:s:t:x:z", + while ((option = getopt_long(argc, argv, "be:fk:l:n:p:qr:s:t:x:z", long_options, &optindex)) != -1) { switch (option) @@ -892,6 +930,25 @@ main(int argc, char **argv) case 'f': config.follow = true; break; + case 'k': + if (sscanf(optarg, "%ul", &config.filter_by_relation_block) != 1) + { + pg_log_error("could not parse block number \"%s\"", optarg); + goto bad_argument; + } + config.filter_by_relation_block_enabled = true; + break; + case 'l': + if (sscanf(optarg, "%d/%d/%d", + &config.filter_by_relation.spcNode, + &config.filter_by_relation.dbNode, + &config.filter_by_relation.relNode) != 3) + { + pg_log_error("could not parse relation from \"%s\" (expecting \"spc/dat/rel\")", optarg); + goto bad_argument; + } + config.filter_by_relation_enabled = true; + break; case 'n': if (sscanf(optarg, "%d", &config.stop_after_records) != 1) { @@ -978,6 +1035,12 @@ main(int argc, char **argv) } } + if (config.filter_by_relation_block_enabled && !config.filter_by_relation_enabled) + { + pg_log_error("cannot filter by --block without also filtering --relation"); + goto bad_argument; + } + if ((optind + 2) < argc) { pg_log_error("too many command-line arguments (first is \"%s\")", @@ -1150,6 +1213,15 @@ main(int argc, char **argv) config.filter_by_xid != record->xl_xid) continue; + /* check for extended filtering */ + if (config.filter_by_relation_enabled && + !XLogRecordMatchesRelationBlock( + xlogreader_state, + config.filter_by_relation, + config.filter_by_relation_block_enabled ? config.filter_by_relation_block : InvalidBlockNumber + )) + continue; + /* perform any per-record work */ if (!config.quiet) { -- 2.32.0 (Apple Git-132)