ALTER TABLE <target table> DISABLE TRIGGER ALL<bulk data insert operations…>ALTER TABLE <target table> ENABLE TRIGGER ALL 1. 技巧5:使用COPY命令 我们建议使用PostgreSQL COPY命令从一个或者多个文件中加载数据。COPY针对批量数据加载进行了优化。它比运行大量Insert语句或者多值Insert更加高效。 COPY <target t...
在一个事务中,默认比例是:select:update_key:update_non_key:delete:insert=14:1:1:1:1。这也是为什么,我们测试出来的TPS和QPS的比例,大概在1:18~20左右。相当于说,一个事务中,有18个读写操作。 ⑧ oltp_update_index.lua更新操作,通过主键进行更新 ⑨ oltp_update_non_index.lua更新操作,不通过索引列 ⑩...
Tip 4: Disable Triggers INSERT or DELETE triggers (if the load process also involves deleting records from the target table) can cause delays in bulk data loading. This is because each trigger will have logic that needs to be checked and operations that need to complete right after each row...
unique index, since the error checking afforded by the unique constraint will be lost while the index is missing. 14.4.4. Remove Foreign Key Constraints Just as with indexes, a foreign key constraint can be checked “in bulk” more efficiently than row-byrow. So it might be useful to drop...
--index-tablespace=TABLESPACE指定索引默认存储表空间 --tablespace=TABLESPACE指定表默认存储表空间 --unlogged-tables指定创建的表不记录日志 select运行选项-b, --builtin=NAME[@W]指定运行脚本 -f, --file=FILENAME[@W]指定运行脚本 -N, --skip-some-updates跳过pgbench_tellers和pgbench_branches的更新 ...
Index support. An engine might not necessarily use all of these components, but the ability is still there. Then, there are things that an engine must define: Row version format and data structure. Table scan routines. Insert, delete, update, and lock routines. Row version visibility rules....
pglogical.alter_subscription_disable(subscription_name name, immediate bool) Disables a subscription and disconnects it from the provider. Parameters: subscription_name - name of the existing subscription immediate - if true, the subscription is stopped immediately, otherwise it will be only stopped at...
6.执行index vacuuming并调用lazy_vacuum_heap回收DEAD行指针 其处理流程如下: 1.初始化相关变量 2.获取总块数(nblocks) 3.初始化统计信息和相关数组(vacrelstats/frozen) 4.计算下一个不能跳过的block(next_unskippable_block) 5.遍历每个block 5.1如已达next_unskippable_block块,计算下一个不能跳过的block ...
Improved the performance of bulk load, parsing of T-SQL and prepared statements. Added a new system stored procedure sp_babelfish_volatility that you can use to set the volatility of user-defined functions to improve index use when the functions are used as part of query predicates. Fixed an...
COPY FROM的实现逻辑比COPY TO相对复杂一些。其原因在于,COPY TO是要把数据库中的数据导出到外部,其中获取数据这一步及其并行优化,很大程度上借助了优化器和执行器的能力,复用了很多代码;而COPY FROM是要把外部数据导入数据库,其中写入数据库的行为因需要更高效的定制实现,而不能复用INSERT相关的执行器代码了。