Wiki / Configuration Parameters
io_combine_limit
Controls the largest I/O size in operations that combine I/O. If set higher than the io_max_combine_limit parameter, the lower value will silently be used instead, so both may need to be raised to increase the I/O size. If this value is specified without units, it is taken as blocks, that is BLCKSZ bytes, typically 8kB. The maximum possible size depends on the operating system and block size, but is typically 1MB on Unix and 128kB on Windows. The default is 128kB.
English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.
Reading PG 18·Select a recorded version
- boot val
- 16
- category
- Resource Usage / I/O
- context
- user
- documented
- true
- enumvals
- Unknown
- extra desc
- Unknown
- lang
- en
- max val
- 128
- metadata version
- 18
- min val
- 1
- name
- io_combine_limit
- short desc
- Limit on the size of data reads and writes.
- source
- pg-settings-source-snapshot
- unit
- 8kB
- vartype
- integer
Definition PG 18
Controls the largest I/O size in operations that combine I/O. If set higher than the io_max_combine_limit parameter, the lower value will silently be used instead, so both may need to be raised to increase the I/O size. If this value is specified without units, it is taken as blocks, that is BLCKSZ bytes, typically 8kB. The maximum possible size depends on the operating system and block size, but is typically 1MB on Unix and 128kB on Windows. The default is 128kB.
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Definition sources
center · PostgreSQL 18 · wiki-repair-20261023:1cd16b6502c2fb7ff126caaa8537f33bea78e575e3ea86be7c84653c8e1f02c8
Text language: en · wiki-repair-20261023:1cd16b6502c2fb7ff126caaa8537f33bea78e575e3ea86be7c84653c8e1f02c8