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Diffstat (limited to 'doc/development/hash_indexes.md')
| -rw-r--r-- | doc/development/hash_indexes.md | 29 |
1 files changed, 7 insertions, 22 deletions
diff --git a/doc/development/hash_indexes.md b/doc/development/hash_indexes.md index 731639b6f06..2a9f7e5a25d 100644 --- a/doc/development/hash_indexes.md +++ b/doc/development/hash_indexes.md @@ -1,26 +1,11 @@ --- -stage: Data Stores -group: Database -info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments +redirect_to: 'database/hash_indexes.md' +remove_date: '2022-11-06' --- -# Hash Indexes +This document was moved to [another location](database/hash_indexes.md). -PostgreSQL supports hash indexes besides the regular B-tree -indexes. Hash indexes however are to be avoided at all costs. While they may -_sometimes_ provide better performance the cost of rehashing can be very high. -More importantly: at least until PostgreSQL 10.0 hash indexes are not -WAL-logged, meaning they are not replicated to any replicas. From the PostgreSQL -documentation: - -> Hash index operations are not presently WAL-logged, so hash indexes might need -> to be rebuilt with REINDEX after a database crash if there were unwritten -> changes. Also, changes to hash indexes are not replicated over streaming or -> file-based replication after the initial base backup, so they give wrong -> answers to queries that subsequently use them. For these reasons, hash index -> use is presently discouraged. - -RuboCop is configured to register an offense when it detects the use of a hash -index. - -Instead of using hash indexes you should use regular B-tree indexes. +<!-- This redirect file can be deleted after <2022-11-06>. --> +<!-- Redirects that point to other docs in the same project expire in three months. --> +<!-- Redirects that point to docs in a different project or site (for example, link is not relative and starts with `https:`) expire in one year. --> +<!-- Before deletion, see: https://docs.gitlab.com/ee/development/documentation/redirects.html --> |