2 回滚事务有多少,(从这点就可以看出某些问题) 3 整体数据库的读写比 , tup_fetched 与 tup_inserted, tup_updated, tup_deleted 和的比率 4 查询数据回馈与实际数据的搜索的比率,也就是查找多少数据返回的行数与对应到底数据库检索了多少行 tup_fetched / tup_returned 5 是否数据库有死锁 等等以上信息。应...
PostgreSQL 磁盘空间的保护伞 PG_repack VS 表膨胀 PG 最近的使用中,发现这个数据库确确实实是一个无底洞,东西太多了,但学习一样东西都是通过主干和分支的方式来学习,后续的学习其实有的时候是靠自觉和运气。 今天要说的pg_repack,这个插件,如果您是第一次看到这篇文字,并且没有接触过PG,那的确可能看上去,PG ...
PostgreSql 数据库统计信息 why when what 统计信息,没有数据是没有的,但统计信息怎么收集,标准是什么,怎么使用,就值得去看看了。 要说统计信息,首先说一个表 pg_statistic ,这个表本身是存储数据库的状态信息,其中信息通过analyze 命令来获得,并存在在这个表里面,并且这个表被用于查询计划中。 既然是统计,那就造...
However, psycopg provides a more efficient method to handle multiple results. After running a query, the first result is immediately available in the cursor and can be fetched using standard methods. To access subsequent results, you can use the cursor.nextset() method....
/** can still fail if it is not allowed e.g. already fetched results **/ RETURN_LONG((zend_long)PQsetChunkedRowsMode(link->conn, (int)size)); Copy link Member GirgiasJun 15, 2024 What value is returned on failure?0? Sorry, something went wrong. ...
The Materialize node will store all of the fetched row(s) into a temporary storage called tuplestore, which allows the previous rows to be accessed again at a later time. The tuplestore will store the fetched row(s) into an in-memory array if their collective size is below a specified ...