vacuumdb 命令

常用示例

说明

vacuumdb cleans and analyzes PostgreSQL databases. It is a wrapper around the SQL VACUUM and ANALYZE commands, providing convenient options for scripting and cron jobs. Regular vacuum marks dead tuples for reuse. It doesn't reclaim disk space but prevents table bloat from growing indefinitely. Full vacuum rewrites tables, reclaiming disk space. It requires an exclusive lock on the table and more time than regular vacuum. Analyze updates statistics used by the query planner. Accurate statistics lead to better query plans and performance. Parallel vacuuming with -j processes multiple tables simultaneously. The -P option controls the number of parallel workers within each vacuum operation.

参数

-a, --all

Vacuum all databases.

-d _DBNAME_, --dbname _DBNAME_

Database to clean or analyze.

-z, --analyze

Also calculate statistics for use by the optimizer.

-Z, --analyze-only

Only calculate statistics, do not vacuum.

--analyze-in-stages

Analyze in three stages with increasing statistics targets. Useful for databases with no or wholly incorrect statistics.

-f, --full

Perform full vacuuming (rewrites tables, reclaims disk space).

-F, --freeze

Aggressively freeze tuples to prevent transaction ID wraparound.

-t _TABLE_, --table _TABLE_

Vacuum specific table only. Can be specified multiple times.

-n _SCHEMA_, --schema _SCHEMA_

Clean or analyze all tables in the specified schema only. Can be specified multiple times.

-N _SCHEMA_, --exclude-schema _SCHEMA_

Exclude tables in the specified schema.

-j _N_, --jobs _N_

Run vacuum or analyze commands in parallel by running N jobs simultaneously.

-P _N_, --parallel _N_

Specify the number of parallel workers for each vacuum operation.

--skip-locked

Skip relations that cannot be immediately locked for processing.

--no-index-cleanup

Do not remove index entries pointing to dead tuples.

--no-truncate

Do not truncate empty pages at the end of the table.

--disable-page-skipping

Disable skipping pages based on the visibility map.

--min-xid-age _AGE_

Only process tables with a transaction ID age of at least AGE.

--min-mxid-age _AGE_

Only process tables with a multixact ID age of at least AGE.

-e, --echo

Echo the commands sent to the server.

-q, --quiet

Do not display progress messages.

-v, --verbose

Print detailed information during processing.

-h _HOST_, --host _HOST_

Database server host.

-p _PORT_, --port _PORT_

Server port.

-U _USER_, --username _USER_

Username to connect as.