select indexrelname, pg_size_pretty(pg_relation_size(relid)) from pg_stat_user_indexes where schemaname='public' order by pg_relation_size(relid) desc; select schemaname ,round(sum(pg_total_relation_size(schemaname||'.'||indexname))/1024/1024) "Size_MB" from pg_indexes where schemaname...
psql: \watch and the number of repetitions psql:\df+ does not show the source code of functions pg_dump: support for LZ4 and zstd compression methods pg_dump and partitioned tables pg_verifybackup --progress libpq: balancing connectionsServer administration and maintenanceinitdb...
You can use this flag if you validate backups regularly and would like to save time when running restore operations. --restore-command=cmdline Sets the restore_command parameter to the specified command. For example: --restore-command='cp /mnt/server/archivedir/%f "%p"' --force Allows to...
When using an index can be slower than not using one How do BRIN indexes work? What does Postgres do with a BRIN index? When to use BRIN indexes Outliers and BRIN indexes Find outliers in BRIN indexes…Continue reading Partitioning in Postgres and the risk of high partition counts27 July,...
which isverygood at doing lots of intersections. It would be interesting to try this withGIN-indexes(inverted index, similar to what Lucene does) in Postgres as a comparison.Bloom-indexesmay also be suited for this. Columnar database might also be better at this, but I haven’t looked at...
What Does a Postgres Index Look Like? Lehman and Yao drew this diagram over 30 years ago -- what does it have to do with how Postgres works today? Astonishingly, the index_users_on_name index we created earlier looks very similar to Figure 2: We created an index in 2014 that looks ju...
string NOT LIKE pattern [ ESCAPE escape-character ] 每个pattern定义一个字串的集合。如果该string包含在pattern代表的字串集合里,那么LIKE表达式返回真。和我们想象的一样,如果LIKE返回真,那么NOT LIKE表达式返回假,反之亦然。在pattern里的下划线(_)代表匹配任何单个字符,而一个百分号(%)匹配任何零或更多字符,如...
3. 数据库情况: 1 master + 1 primary + 1 mirror 1. 数据库版本: PostgreSQL 8.2.15 (Greenplum Database 4.3.25.1 build 1) 1. psql帮助手册指南: testdb=# \? General \copyright show PostgreSQL usage and distribution terms \g [FILE] or ; execute query (and send results to file or |pipe...
Other data objects won't be replicated to the destination like indexes, permissions. Multiple methods of keeping your data fresh, including Change Data Capture (CDC) and replication using the xmin system column. All available sync modes, providing flexibility in how data is delivered to your ...
reading the Postgres C source code — was the Computer Science theory behind what it was doing. Reading the Postgres source was like going back to school and taking that class I never had time for when I was younger. The C comments inside Postgres not only explain what Postgres does, but...