{"id":256,"date":"2025-07-24T20:08:14","date_gmt":"2025-07-24T12:08:14","guid":{"rendered":"https:\/\/yuzikimikage.top\/?p=256"},"modified":"2025-07-24T20:08:14","modified_gmt":"2025-07-24T12:08:14","slug":"xlog","status":"publish","type":"post","link":"https:\/\/yuzikimikage.top\/index.php\/2025\/07\/24\/xlog\/","title":{"rendered":"xlog\u3055\u307e\u3056\u307e"},"content":{"rendered":"\n

1 xlog<\/h1>\n\n\n\n

1.1 \u7b80\u4ecb<\/h2>\n\n\n\n

\u5728PG\u4e2d\uff0c\u4efb\u4f55\u4fee\u6539\u6570\u636e\u5e93\u7684\u64cd\u4f5c\u90fd\u4f1a\u8bb0\u5f55\u4e00\u4efd\u65e5\u5fd7\uff0c\u8fd9\u4e2a\u65e5\u5fd7\u5c31\u53eb\u505axlog\u3002\u57289.2.4\u7248\u672c\u4e2d\uff0cxlog\u65e5\u5fd7\u7684\u76ee\u5f55\u662fPGDATA\/pg_xlog\uff0c\u5728\u66f4\u9ad8\u7684\u7248\u672c\u91cc\uff0c\u8be5\u76ee\u5f55\u53d8\u6210\u4e86$PGDATA\/pg_wal<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

WAL\uff08Write-Ahead Logging\uff0c\u9884\u5199\u65e5\u5fd7\uff09\u662f\u4e00\u79cd\u7528\u4e8e\u786e\u4fdd\u6570\u636e\u5e93\u6570\u636e\u4e00\u81f4\u6027\u548c\u6062\u590d\u80fd\u529b\u7684\u6280\u672f\u3002XLOG \u6587\u4ef6\u5c31\u662f WAL \u7684\u7269\u7406\u5b58\u50a8\u5f62\u5f0f\uff0c\u5b83\u8bb0\u5f55\u4e86\u6240\u6709\u4fee\u6539\u6570\u636e\u5e93\u5185\u5bb9\u7684\u64cd\u4f5c\uff0c\u5305\u62ec\u6570\u636e\u7684\u63d2\u5165\u3001\u66f4\u65b0\u3001\u5220\u9664\u4ee5\u53ca\u5143\u6570\u636e\u7684\u53d8\u66f4\u7b49<\/p>\n\n\n\n

wal_level\u53c2\u6570\u5f71\u54cdwal\u65e5\u5fd7\u7684\u8be6\u7ec6\u7a0b\u5ea6\uff1a<\/p>\n\n\n\n

minimal\uff1a\u6700\u4f4e\u7684\u65e5\u5fd7\u7ea7\u522b\uff0c\u4ec5\u8bb0\u5f55\u8db3\u4ee5\u4fdd\u8bc1\u5d29\u6e83\u6062\u590d\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n

Replica\uff1a\u63d0\u4f9b\u8db3\u591f\u65e5\u5fd7\u4fe1\u606f\u652f\u6301\u70ed\u5907\u548c\u6d41\u590d\u5236\uff0c\u8bb0\u5f55\u6240\u6709\u4e8b\u52a1\u7684\u53d8\u66f4\uff0c\u5305\u62ec\u7d22\u5f15\u53d8\u66f4\u548c\u884c\u7248\u672c\u4fe1\u606f<\/p>\n\n\n\n

Logical\uff1a\u63d0\u4f9b\u6700\u8be6\u7ec6\u7684\u65e5\u5fd7\u8bb0\u5f55\uff0c\u5305\u62ec\u6240\u6709\u903b\u8f91\u53d8\u66f4<\/p>\n\n\n\n

1.2 Xlog\u7684\u5927\u5c0f<\/h2>\n\n\n\n

Wal\u7531\u591a\u4e2asegment\u7ec4\u6210\uff0c\u800c\u4e00\u4e2asegment\u53c8\u662f\u7531\u591a\u4e2apage\u7ec4\u6210\u7684\uff0c\u5176\u5927\u5c0f\u5b9a\u4e49\u5728src\/include\/pg_config.h \u4e2d<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u9ed8\u8ba4\u5927\u5c0f\uff1aXLOG_BLCKSZ   8K\uff1a\u4e00\u6b21\u5199\u51658K<\/p>\n\n\n\n

XLOG_SEG_SIZE 16M\uff1a\u4e00\u4e2aseg\u5199\u6ee1\u4e3a16MB<\/p>\n\n\n\n

\u53ea\u5141\u8bb8\u5728\u7f16\u8bd1\u7684\u65f6\u5019\u4fee\u6539\u3002<\/p>\n\n\n\n

wal segment\u7684\u5927\u5c0f\u7531\u53c2\u6570wal_block_size\u63a7\u5236\uff0c\u7f16\u8bd1\u4e4b\u540e\u65e0\u6cd5\u4fee\u6539<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

1.3 Xlog\u7684\u521d\u59cb\u5316<\/h2>\n\n\n\n

\u5bf9\u5e94\u4e8exlog\uff0c\u5176\u521d\u59cb\u5316\u7684\u5165\u53e3\u51fd\u6570\u662fBootStrapXLOG\uff0c\u8be5\u51fd\u6570\u53ea\u4f1a\u5728\u521d\u59cb\u5316\u7684\u65f6\u5019\u8c03\u7528\u4e00\u6b21\uff0c\u4e3b\u8981\u7528\u4e8e\u521b\u5efapg_control\u6587\u4ef6\u548c\u521d\u59cb\u5316\u7b2c\u4e00\u4e2axlog segment\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Xlog\u7684\u547d\u540d\u89c4\u5219\uff1a<\/p>\n\n\n\n

\u5728PG10\u4e4b\u524d\u7684\u7248\u672c\u4e2d\uff0c\u75313\u4e2a\u53c2\u6570\u7ec4\u6210\u517124\u4f4d\u7684\u5341\u516d\u8fdb\u5236\u5b57\u7b26\u4e32\uff0c\u6bcf\u4e2a\u53c2\u6570\u53608\u4f4d\u3002<\/p>\n\n\n\n

\u4e09\u4e2a\u53c2\u6570\u5206\u522b\u4e3a\uff1atli\u3001log\u3001seg<\/p>\n\n\n\n

-rw------- 1 postgres postgres 16777216 Jul 22 18:27 00000001000000000000003B<\/code><\/pre>\n\n\n\n
\u5bf9\u5e94\u8fd9\u4e2a\u6587\u4ef6<\/p>\n\n\n\n
Tli\uff08\u5b8c\u6574\u540d\u79f0\u662ftimeline\uff1a\u8868\u793a\u6570\u636e\u5e93\u7684\u72b6\u6001\uff0c\u5728\u6570\u636e\u6062\u590d\u540e\u4f1a\u53d1\u751f\u53d8\u5316\uff09\uff1a00000001<\/p>\n\n\n\n
Log file ID\uff1a00000000<\/p>\n\n\n\n
Segment\uff1a0000003B<\/p>\n\n\n\n
\u800c\u5728PG10\u4e4b\u540e\uff0cLog file ID\u548csegment\u5408\u5e76\u4e3a\u4e00\u4e2a\u53c2\u6570\uff08Log_segment_number\uff09<\/p>\n\n\n\n
1.4 Xlog\u6587\u4ef6\u7684\u4f5c\u7528<\/h2>\n\n\n\n
    \n
  • \u6570\u636e\u6062\u590d<\/li>\n<\/ul>\n\n\n\n
    \u5728\u7cfb\u7edf\u5d29\u6e83\u6216\u53d1\u751f\u6545\u969c\u540e\uff0cXLOG \u6587\u4ef6\u53ef\u4ee5\u7528\u6765\u6062\u590d\u6570\u636e\u5e93\u5230\u4e00\u81f4\u7684\u72b6\u6001\u3002PostgreSQL \u901a\u8fc7\u91cd\u653e\uff08replay\uff09XLOG \u4e2d\u7684\u8bb0\u5f55\u6765\u91cd\u5efa\u4e8b\u52a1\uff0c\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002<\/p>\n\n\n\n
      \n
    • \u590d\u5236<\/li>\n<\/ul>\n\n\n\n
      \u5728\u6d41\u590d\u5236\uff08streaming replication\uff09\u4e2d\uff0cXLOG \u6587\u4ef6\u7684\u5185\u5bb9\u4f1a\u88ab\u53d1\u9001\u5230\u4ece\u670d\u52a1\u5668\uff08standby server\uff09\uff0c\u4ee5\u4fbf\u4ece\u670d\u52a1\u5668\u53ef\u4ee5\u540c\u6b65\u4e3b\u670d\u52a1\u5668\uff08master server\uff09\u7684\u72b6\u6001\u3002<\/p>\n\n\n\n
        \n
      • \u5f52\u6863<\/li>\n<\/ul>\n\n\n\n
        XLOG \u6587\u4ef6\u53ef\u4ee5\u88ab\u5f52\u6863\uff08archiving\uff09\uff0c\u8fd9\u6837\u5373\u4f7f\u5728\u78c1\u76d8\u7a7a\u95f4\u6709\u9650\u7684\u60c5\u51b5\u4e0b\uff0c\u4e5f\u53ef\u4ee5\u4fdd\u7559\u4e00\u5b9a\u65f6\u95f4\u7684\u5386\u53f2\u65e5\u5fd7\u8bb0\u5f55\u3002<\/p>\n\n\n\n
        1.5 \u4ec0\u4e48\u65f6\u5019\u4f1a\u4ea7\u751f\u65b0\u7684xlog segment<\/h2>\n\n\n\n
          \n
        • \u5f53\u524d\u7684WAL\u6bb5\u6587\u4ef6\u5df2\u6ee1<\/li>\n<\/ul>\n\n\n\n
          \u5f53\u524d\u7684wal segment\u6587\u4ef6\u5199\u6ee1\u65f6\uff0cPostgresql\u4f1a\u521b\u5efa\u65b0\u7684segment\u6587\u4ef6\uff0c\u9ed8\u8ba4\u5927\u5c0f\u662f16MB<\/p>\n\n\n\n
            \n
          • \u68c0\u67e5\u70b9<\/li>\n<\/ul>\n\n\n\n
            \u68c0\u67e5\u70b9\u671f\u95f4\uff0c\u4f1a\u5f3a\u5236\u5c06\u5185\u5b58\u4e2d\u7684\u6570\u636e\u5199\u5165\u78c1\u76d8\uff0c\u5e76\u751f\u6210\u65b0\u7684segment\u6587\u4ef6\u3002<\/p>\n\n\n\n
            \u68c0\u67e5\u70b9\u7684\u89e6\u53d1\u6761\u4ef6\u5305\u62ec\uff1a<\/p>\n\n\n\n
            \u65f6\u95f4\u95f4\u9694\uff1a\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u68c0\u67e5\u70b9\u6bcf5min\u89e6\u53d1\u4e00\u6b21\uff08checkpoint_timeout\uff09<\/p>\n\n\n\n
            WAL\u6587\u4ef6\u5927\u5c0f\uff1a\u5f53wal\u6587\u4ef6\u7684\u5927\u5c0f\u8fbe\u5230\u4e00\u5b9a\u9608\u503c\u65f6\uff0c\u4e5f\u4f1a\u89e6\u53d1\u68c0\u67e5\u70b9<\/p>\n\n\n\n
            \u624b\u52a8\u89e6\u53d1\uff1acheckpoint\u547d\u4ee4<\/p>\n\n\n\n
            \u7f6e\u6362\u810f\u9875\uff08\u9690\u6027\u6761\u4ef6\uff09\uff1a\u5185\u5b58\u4e2d\u7f6e\u6362\u810f\u9875\u4e5f\u4f1a\u89e6\u53d1\u68c0\u67e5\u70b9<\/p>\n\n\n\n
              \n
            • Wal\u65e5\u5fd7\u5207\u6362<\/li>\n<\/ul>\n\n\n\n
              select pg_switch_wal();<\/p>\n\n\n\n
              1.6 \u4ec0\u4e48\u6837\u7684wal segment\u4f1a\u88ab\u6e05\u7406<\/h2>\n\n\n\n
              1.\u5728\u5f00\u542f\u5f52\u6863archive_mode=on\u7684\u60c5\u51b5\u4e0b\uff1a\u5f52\u6863\u6210\u529f\uff08.done\uff09\u7684wal segment\u4f1a\u88ab\u5220\u9664\u3002<\/p>\n\n\n\n
              2.\u5728\u6709\u590d\u5236\u69fd\u7684\u60c5\u51b5\u4e0b\uff0c\u5f53\u6240\u6709\u590d\u5236\u69fd\u7684restart_lsn\u5df2\u7ecf\u8d85\u8fc7\u4e86\u5f53\u524dwal_segment\u7684lsn\uff0c\u90a3\u4e48\u8be5wal\u4f1a\u88ab\u5220\u9664\u3002<\/p>\n\n\n\n
              3.\u68c0\u67e5\u70b9\u89e6\u53d1\uff0c\u786e\u5b9a\u8be5segment\u4e0d\u88ab\u4efb\u4f55\u4e8b\u52a1\u6216\u6062\u590d\u64cd\u4f5c\u9700\u8981<\/p>\n\n\n\n
              4.\u6d41\u590d\u5236\uff1a\u4e0e\u53c2\u6570synchronous_commit\u6709\u5173<\/p>\n\n\n\n
                \n
              • off<\/strong>\uff1a\u4e8b\u52a1\u63d0\u4ea4\u4e0d\u9700\u8981\u7b49\u5f85\u4efb\u4f55\u786e\u8ba4\uff0c\u5373\u4e0d\u7b49\u5f85WAL\u8bb0\u5f55\u88ab\u5199\u5165\u78c1\u76d8\u6216\u5907\u5e93\u3002<\/li>\n\n\n\n
              • local<\/strong>\uff1a\u4e8b\u52a1\u63d0\u4ea4\u9700\u8981\u7b49\u5f85WAL\u8bb0\u5f55\u88ab\u5199\u5165\u672c\u5730\u78c1\u76d8\u3002<\/li>\n\n\n\n
              • remote_write<\/strong>\uff1a\u4e8b\u52a1\u63d0\u4ea4\u9700\u8981\u7b49\u5f85WAL\u8bb0\u5f55\u88ab\u5199\u5165\u81f3\u5c11\u4e00\u4e2a\u5907\u5e93\u7684\u78c1\u76d8\u3002<\/li>\n\n\n\n
              • remote_apply<\/strong>\uff1a\u4e8b\u52a1\u63d0\u4ea4\u9700\u8981\u7b49\u5f85WAL\u8bb0\u5f55\u88ab\u81f3\u5c11\u4e00\u4e2a\u5907\u5e93\u63a5\u6536\u5e76\u5e94\u7528\u3002<\/li>\n\n\n\n
              • on<\/strong>\uff1a\u7b49\u540c\u4e8e remote_write\uff0c\u4e8b\u52a1\u63d0\u4ea4\u9700\u8981\u7b49\u5f85WAL\u8bb0\u5f55\u88ab\u81f3\u5c11\u4e00\u4e2a\u5907\u5e93\u5199\u5165\u78c1\u76d8\u3002<\/li>\n<\/ul>\n\n\n\n
                1.7 wal segment\u7684\u81ea\u52a8\u6e05\u7406\u7684\u65f6\u673a<\/h2>\n\n\n\n
                \u68c0\u67e5\u70b9\u4f1a\u89e6\u53d1WAL\u6bb5\u6587\u4ef6\u7684\u6e05\u7406<\/p>\n\n\n\n
                1.8 wal segment\u7684\u4fdd\u7559\u53d7\u4ec0\u4e48\u53c2\u6570\u5f71\u54cd<\/h2>\n\n\n\n
                wal\u65e5\u5fd7\u7684\u4fdd\u7559\u53d7\u591a\u4e2a\u53c2\u6570\u5f71\u54cd\uff1a<\/p>\n\n\n\n
                  \n
                1. archive_mode\uff1a\u63a7\u5236\u662f\u5426\u5f00\u542fWAL\u5f52\u6863\u3002\u5f53\u8bbe\u7f6e\u4e3aon\u6216always\u65f6\uff0c\u4f1a\u89e6\u53d1archive_command\u8fdb\u884cWAL\u6587\u4ef6\u7684\u5f52\u6863\u64cd\u4f5c\u3002<\/li>\n\n\n\n
                2. archive_command\uff1a\u6307\u5b9a\u5c06WAL\u590d\u5236\u5230\u5916\u90e8\u4ecb\u8d28\u7684Shell\u547d\u4ee4\u3002\u5982\u679c\u547d\u4ee4\u8fd4\u56de\u975e0\uff0cPostgreSQL\u4f1a\u65e0\u9650\u91cd\u8bd5\uff0c\u5bfc\u81f4WAL\u5806\u79ef\u3002<\/li>\n\n\n\n
                3. archive_timeout\uff1a\u5f53\u67d0\u4e2asegment\u6700\u540e\u4e00\u6b21\u5199\u5165\u8ddd\u4eca\u8d85\u8fc7\u8be5\u79d2\u6570\u65f6\u5f3a\u5236\u5207\u6362WAL\uff0c\u9632\u6b62\u4f4e\u8d1f\u8f7d\u4e0bWAL\u957f\u65f6\u95f4\u4e0d\u5f52\u6863\uff0c\u4f46\u4f1a\u589e\u52a0\u6587\u4ef6\u6570\u91cf\u3002<\/li>\n\n\n\n
                4. max_wal_size\uff1aWAL\u76ee\u5f55\u8f6f\u4e0a\u9650\u3002\u5f53WAL\u7d2f\u79ef\u8d85\u8fc7\u8be5\u503c\u65f6\uff0c\u5f3a\u5236\u89e6\u53d1checkpoint\uff0c\u671f\u671b\u901a\u8fc7\u56de\u6536\/\u5220\u9664\u964d\u4f4e\u5927\u5c0f\u3002<\/li>\n\n\n\n
                5. min_wal_size\uff1aWAL\u76ee\u5f55\u8f6f\u4e0b\u9650\u3002\u4e00\u6b21checkpoint\u7ed3\u675f\u540e\uff0cPostgreSQL\u4f1a\u5c1d\u8bd5\u5c06WAL\u5927\u5c0f\u6536\u7f29\u5230\u4e0d\u4f4e\u4e8e\u8be5\u503c\u3002<\/li>\n\n\n\n
                6. wal_keep_segments\uff1a\u5373\u4f7f\u5f52\u6863\/\u590d\u5236\u5747\u5df2\u5b8c\u6210\uff0c\u4e5f\u5fc5\u987b\u5728pg_wal\u4e2d\u4fdd\u7559\u6700\u8fd1N\u4e2asegment\u3002<\/li>\n\n\n\n
                7. max_slot_wal_keep_size\uff1a\u5728PostgreSQL 13\u53ca\u4ee5\u4e0a\u7248\u672c\u4e2d\uff0c\u7528\u4e8e\u63a7\u5236\u590d\u5236\u69fd\u4fdd\u7559\u7684\u6700\u5927\u65e5\u5fd7\u91cf\u3002<\/li>\n\n\n\n
                8. wal_keep_size\uff1a\u5728PostgreSQL 13\u53ca\u4ee5\u4e0a\u7248\u672c\u4e2d\uff0c\u4ee5MB\u5b9a\u4e49\u7684\u66ff\u4ee3wal_keep_segments\uff0c\u540c\u6837\u5c5e\u4e8e\u786c\u7ea6\u675f\u7a97\u53e3\u3002<\/li>\n\n\n\n
                9. checkpoint_timeout\uff1a\u4e24\u6b21checkpoint\u6700\u957f\u95f4\u9694\u3002\u95f4\u9694\u8d8a\u957f\uff0cWAL\u8d8a\u591a\uff1b\u4f46\u8fc7\u77ed\u4f1a\u5bfc\u81f4I\/O\u6296\u52a8\u3002<\/li>\n\n\n\n
                10. checkpoint_completion_target\uff1acheckpoint\u6301\u7eed\u65f6\u95f4\u5360\u95f4\u9694\u6bd4\u4f8b\u3002\u8f83\u5927\u503c\u53ef\u5e73\u6ed1I\/O\uff0c\u964d\u4f4eWAL\u5cf0\u503c\u3002<\/li>\n<\/ol>\n\n\n\n
                  2 \u5f52\u6863xlog<\/h1>\n\n\n\n
                  2.1\u4e3a\u4ec0\u4e48\u8981\u5f52\u6863<\/h2>\n\n\n\n
                  \u5c06wal\u65e5\u5fd7\u79fb\u52a8\u5230\u4e00\u4e2a\u5b89\u5168\u7684\u4f4d\u7f6e\u3002<\/p>\n\n\n\n
                  \u901a\u8fc7\u5408\u7406\u914d\u7f6e\u548c\u7ba1\u7406wal\u5f52\u6863\uff0c\u53ef\u4ee5\u663e\u8457\u63d0\u9ad8\u6570\u636e\u5e93\u7684\u53ef\u9760\u6027\u548c\u5b89\u5168\u6027\u3002<\/p>\n\n\n\n
                  pg_wal\/archive_status\/\u4e0b\u7684\u6587\u4ef6\u8868\u793a\u5bf9\u5e94wal\u7684\u5f52\u6863\u72b6\u6001\uff1a<\/p>\n\n\n\n
                  .done\uff1a\u8868\u793a\u5df2\u7ecf\u5f52\u6863<\/p>\n\n\n\n
                  .ready\uff1a\u8868\u793a\u53ef\u4ee5\u8fdb\u884c\u5f52\u6863\uff0c\u5f52\u6863\u5b8c\u6210\u540e\uff0c.ready\u4f1a\u53d8\u4e3a.done<\/p>\n\n\n\n
                  \u8fd9\u4e9b\u6587\u4ef6\u90fd\u6ca1\u6709\u5185\u5bb9\uff0c\u53ea\u662f\u4e2a\u7a7a\u6587\u4ef6<\/p>\n\n\n\n
                  2.2\u4ec0\u4e48\u65f6\u5019\u89e6\u53d1\u5f52\u6863<\/h2>\n\n\n\n
                  \u4ea7\u751f\u65b0\u7684wal segment<\/p>\n\n\n\n
                  \u8fbe\u5230archive_timeout\u53c2\u6570\u8bbe\u7f6e\u7684\u8d85\u65f6\u65f6\u95f4<\/p>\n\n\n\n
                  \u68c0\u67e5\u70b9\u89e6\u53d1\uff1a\u4f1a\u5c06\u5185\u5b58\u4e2d\u7684\u6570\u636e\u5199\u5165\u78c1\u76d8\uff0c\u53ef\u80fd\u56e0\u6b64\u4ea7\u751f\u65b0\u7684wal segment<\/p>\n\n\n\n
                  2.3\u5f52\u6863\u65e5\u5fd7\u7684\u6e05\u7406<\/h2>\n\n\n\n
                  \u5f52\u6863\u76ee\u5f55\u7684xlog\u6587\u4ef6\u7684\u81ea\u52a8\u6e05\u7406\u4e3b\u8981\u4f9d\u8d56\u4e8e\u53c2\u6570archive_cleanup_command\u7684\u914d\u7f6e\uff0c\u5728\u6bcf\u6b21wal segment\u6210\u529f\u5f52\u6863\u540e\u81ea\u52a8\u6267\u884c\uff0c\u6e05\u7406\u4e0d\u518d\u9700\u8981\u7684\u65e7\u65e5\u5fd7\u6587\u4ef6\u3002<\/p>\n\n\n\n
                  \u5177\u4f53\u54ea\u4e9b\u6587\u4ef6\u4f1a\u88ab\u6e05\u7406\uff0c\u8981\u770barchive_cleanup_command\u7684\u5177\u4f53\u914d\u7f6e\u3002<\/p>\n\n\n\n
                  \u82e5\u672a\u914d\u7f6e\u4ee5\u4e0a\u53c2\u6570\uff0c\u5219\u9700\u8981\u5728\u64cd\u4f5c\u7cfb\u7edf\u5c42\u9762\u8bbe\u7f6e\u5b9a\u65f6\u4efb\u52a1\u6765\u6e05\u7406\u3002<\/p>\n\n\n\n
                  \u82e5\u4e24\u8005\u90fd\u672a\u914d\u7f6e\uff0c\u5219\u5f52\u6863\u76ee\u5f55\u4e0b\u7684xlog\u4f1a\u4e0d\u65ad\u5806\u79ef\u3002<\/p>\n\n\n\n
                  3 Xlog\u5185\u5bb9\u89e3\u6790<\/h1>\n\n\n\n
                  \u4ecexlog\u6587\u4ef6\u4e2d\u53ef\u4ee5\u83b7\u53d6\u5982\u4e0b\u4fe1\u606f\uff1a<\/p>\n\n\n\n
                    \n
                  1. \u64cd\u4f5c\u5bf9\u8c61\uff1a\u7d22\u5f15\u8fd8\u662f\u8868<\/li>\n\n\n\n
                  2. \u8bb0\u5f55\u957f\u5ea6<\/li>\n\n\n\n
                  3. \u4e8b\u52a1\u7f16\u53f7<\/li>\n\n\n\n
                  4. Lsn<\/li>\n\n\n\n
                  5. \u64cd\u4f5c\u7c7b\u578b\uff1a\u589e\u3001\u5220\u3001\u6539<\/li>\n\n\n\n
                  6. \u5b9e\u9645\u64cd\u4f5c\u5bf9\u8c61<\/li>\n<\/ol>\n\n\n\n
                    \u4e3e\u4f8b\uff1a<\/strong><\/p>\n\n\n\n
                    \u4e0b\u9762\u662f\u4f7f\u7528pg_waldump\u89e3\u6790\u4e00\u4e2axlog\u6587\u4ef6\u540e\u5f97\u5230\u7684\u7ed3\u679c<\/p>\n\n\n\n
                    pg_waldump 000000xxxxxxx<\/p>\n\n\n\n
                    \"\"<\/figure>\n\n\n\n
                    \u4e0b\u9762\u662f\u5bf9\u6bcf\u4e00\u884c\u8f93\u51fa\u7684\u89e3\u91ca\uff1a<\/p>\n\n\n\n
                    rmgr\uff1aB-tree<\/td>\u8868\u793a\u8fd9\u4e2a\u8bb0\u5f55\u662f\u7531B-Tree\u7d22\u5f15\u7ba1\u7406\u5668\u751f\u6210\u7684<\/td><\/tr>
                    rmgr: Heap<\/td>\u8868\u793a\u8fd9\u6761\u8bb0\u5f55\u662f\u7531Heap\u8868\u7ba1\u7406\u5668\u751f\u6210\u7684\u3002 Heap\u8868\u793a\u64cd\u4f5c\u5bf9\u8c61\u662f\u8868\u3001\u800cB-Tree\u8868\u793a\u64cd\u4f5c\u5bf9\u8c61\u662f\u7d22\u5f15\u3002<\/td><\/tr>
                    len (rec\/tot): 64\/64<\/td>\u8868\u793a\u8fd9\u4e2a\u8bb0\u5f55\u7684\u957f\u5ea6\u662f64\u5b57\u8282\uff0c\u603b\u5171\u4e5f\u662f64\u5b57\u8282<\/td><\/tr>
                    tx\uff1a<\/td>\u8868\u793a\u4e8b\u52a1\u7f16\u53f7<\/td><\/tr>
                    lsn<\/td>\u8868\u793a\u8fd9\u6761\u8bb0\u5f55\u7684\u65e5\u5fd7\u5e8f\u5217\u53f7<\/td><\/tr>
                    prev<\/td>\u8868\u793a\u8fd9\u6761\u8bb0\u5f55\u7684\u524d\u4e00\u6761\u8bb0\u5f55\u7684LSN<\/td><\/tr>
                    desc<\/td>\u63cf\u8ff0\u4e86\u8fd9\u4e2a\u8bb0\u5f55\u7684\u64cd\u4f5c\u7c7b\u578b\u3002 INSERT_LEAF off 324\u8868\u793a\u5728B-Tree\u7684\u53f6\u5b50\u8282\u70b9\u4e0a\u6267\u884c\u4e86\u4e00\u4e2aINSERT\u64cd\u4f5c\uff0c\u504f\u79fb\u91cf\u662f324<\/td><\/tr>
                    blkref<\/td>\u8868\u793a\u8fd9\u4e2a\u64cd\u4f5c\u6d89\u53ca\u5230\u7684\u5173\u7cfb\u6216\u8005\u7d22\u5f15\u7684oid\uff0c\u4ee5\u53ca\u5bf9\u5e94\u7684\u5757\u53f7<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
                    \u6709\u4e86\u4ee5\u4e0a\u7684\u4fe1\u606f\uff0c\u4e3b\u8981\u662f\u6709\u4e86desc\u548coid\uff0c\u6211\u4eec\u5c31\u80fd\u591f\u5177\u4f53\u5230\u6570\u636e\u5e93\u7684\u67d0\u4e00\u5f20\u8868\u4e0a\u7684\u5177\u4f53\u64cd\u4f5c\u3002<\/p>\n\n\n\n
                    4 \u6d41\u590d\u5236\u548c\u590d\u5236\u69fd<\/h1>\n\n\n\n
                    4.1 \u6d41\u590d\u5236<\/h2>\n\n\n\n
                    \u6d41\u590d\u5236\u662f\u4e00\u79cd\u673a\u5236\uff0c\u4e3b\u5e93\u5c06wal\u5b9e\u65f6\u53d1\u9001\u5230\u4ece\u5e93\uff0c\u5b9e\u65f6\u540c\u6b65<\/p>\n\n\n\n
                    \u4ece\u5e93\u901a\u8fc7pg_basebackup\u6216\u5176\u4ed6\u5de5\u5177\u4ece\u4e3b\u5e93\u83b7\u53d6\u521d\u59cb\u5907\u4efd\uff0c\u901a\u8fc7postgresql.conf\u8fde\u63a5\u5230\u4e3b\u5e93\uff0c\u5b9e\u65f6\u63a5\u6536WAL\u5e76\u5e94\u7528<\/p>\n\n\n\n
                    4.2 \u590d\u5236\u69fd<\/h2>\n\n\n\n
                    \u4e3b\u5907\u901a\u8fc7\u590d\u5236\u69fd\u63a5\u6536\u548c\u63a8\u9001wal\u65e5\u5fd7\uff0c\u6709\u4e00\u5b9a\u5ef6\u8fdf<\/p>\n\n\n\n
                    <\/p>\n","protected":false},"excerpt":{"rendered":"
                    1 xlog 1.1 \u7b80\u4ecb \u5728PG\u4e2d\uff0c\u4efb\u4f55\u4fee\u6539\u6570\u636e\u5e93\u7684\u64cd\u4f5c\u90fd\u4f1a\u8bb0\u5f55\u4e00\u4efd\u65e5\u5fd7\uff0c\u8fd9\u4e2a\u65e5\u5fd7\u5c31\u53eb\u505axlog\u3002\u57289.2.4\u7248\u672c\u4e2d\uff0cxlog\u65e5 …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"emotion":"","emotion_color":"","title_style":"","license":"","footnotes":""},"categories":[22],"tags":[],"class_list":["post-256","post","type-post","status-publish","format-standard","hentry","category-22"],"_links":{"self":[{"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/posts\/256","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/comments?post=256"}],"version-history":[{"count":3,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/posts\/256\/revisions"}],"predecessor-version":[{"id":266,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/posts\/256\/revisions\/266"}],"wp:attachment":[{"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/media?parent=256"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/categories?post=256"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yuzikimikage.top\/index.php\/wp-json\/wp\/v2\/tags?post=256"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}