开发快照。 PostgreSQL 20devel 尚未正式发布，内容仍可能变化。
F.28. pg_logicalinspect — 逻辑解码组件检查 #
pg_logicalinspect 模块提供 SQL 函数，允许你检查逻辑解码组件的内容。它还允许检查运行中的 PostgreSQL 数据库集簇的序列化逻辑快照，这对调试或教学用途很有帮助。
默认情况下，这些函数仅允许超级用户和 pg_read_server_files 角色成员使用。超级用户可通过 GRANT 向其他用户授予访问权限。
F.28.1. 函数 #
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pg_get_logical_snapshot_meta(filename text) returns record# 获取位于服务器
pg_logical/snapshots目录中的快照文件的逻辑快照元数据。filename参数表示快照文件名。例如：postgres=# SELECT * FROM pg_ls_logicalsnapdir(); -[ RECORD 1 ]+----------------------- name | 0-40796E18.snap size | 152 modification | 2024-08-14 16:36:32+00 postgres=# SELECT * FROM pg_get_logical_snapshot_meta('0-40796E18.snap'); -[ RECORD 1 ]-------- magic | 1369563137 checksum | 1028045905 version | 6 postgres=# SELECT ss.name, meta.* FROM pg_ls_logicalsnapdir() AS ss, pg_get_logical_snapshot_meta(ss.name) AS meta; -[ RECORD 1 ]------------- name | 0-40796E18.snap magic | 1369563137 checksum | 1028045905 version | 6如果
filename不是某个快照文件名，则函数报错。-
pg_get_logical_snapshot_info(filename text) returns record# 获取位于服务器
pg_logical/snapshots目录中的快照文件的逻辑快照信息。filename参数表示快照文件名。例如：postgres=# SELECT * FROM pg_ls_logicalsnapdir(); -[ RECORD 1 ]+----------------------- name | 0-40796E18.snap size | 152 modification | 2024-08-14 16:36:32+00 postgres=# SELECT * FROM pg_get_logical_snapshot_info('0-40796E18.snap'); -[ RECORD 1 ]------------+----------- state | consistent xmin | 751 xmax | 751 start_decoding_at | 0/40796AF8 two_phase_at | 0/40796AF8 initial_xmin_horizon | 0 building_full_snapshot | f in_slot_creation | f last_serialized_snapshot | 0/00000000 next_phase_at | 0 committed_count | 0 committed_xip | catchange_count | 2 catchange_xip | {751,752} postgres=# SELECT ss.name, info.* FROM pg_ls_logicalsnapdir() AS ss, pg_get_logical_snapshot_info(ss.name) AS info; -[ RECORD 1 ]------------+---------------- name | 0-40796E18.snap state | consistent xmin | 751 xmax | 751 start_decoding_at | 0/40796AF8 two_phase_at | 0/40796AF8 initial_xmin_horizon | 0 building_full_snapshot | f in_slot_creation | f last_serialized_snapshot | 0/00000000 next_phase_at | 0 committed_count | 0 committed_xip | catchange_count | 2 catchange_xip | {751,752}如果
filename不是某个快照文件名，则函数报错。
F.28.2. 作者 #
Bertrand Drouvot <bertranddrouvot.pg@gmail.com>