Note that on many systems, the effective resolution of sleep delays is 10 milliseconds; setting wal_writer_delay to a value that is not a multiple of 10 might have the same results as setting it to the next higher multiple of 10. This parameter can only be set in the postgresql.conf ...
PostgreSQL CASEs can have multiple conditions. There are a handful of entries in the table where the name of country and capital is the same. You can add this to your previously constructed CASE - SELECT name, continent, indep_year, CASE WHEN (indep_year < 1900) AND (countries.name = co...
对于ANALYZE这种工具性质的指令,执行器代码通过standard_ProcessUtility()函数中的 switch case 将每一种指令路由到实现相应功能的函数中。 /** standard_ProcessUtility itself deals only with utility commands for* which we do not provide event trigger support. Commands that do have* such support are passed...
测试使用make check或make installcheck进行,它会通过pg_regress程序调用sql目录中的SQL,并收集输出结果(通常放到results目录中),最后pg_regress会对expected目录和results目录中的文件使用diff进行一一比较。 如果比较发现文件内容不一致,会将不一致的结果输出到regression.diffs文件中,并返回这个TEST CASE failed。 但是这...
ETCD and PGSQL are used for HA PG clusters; Installing them on multiple nodes automatically forms HA clusters. The default install.yml playbook will install INFRA, NODE, ETCD & PGSQL on the current node. Which gives you an out-of-the-box PostgreSQL singleton instance (admin_ip:5432) with...
if [[ "$nr_out" != "$nr_option=no" ]]; then error $"Note that systemd configuration for '$option_service' changed." error_q $"You need to perform 'systemctl daemon-reload' otherwise the" error_q $"results of this script can be inadequate."exit 1 ...
WHEN SUBSTRING(username, 1, 1) BETWEEN 'A' AND 'M' THEN 'Group A-M' ELSE 'Group N-Z' END AS user_group FROM users; Furthermore, you can even combine results using the CONCAT function: SELECT username, CONCAT('Belongs to: ', CASE WHEN SUBSTRING(username, 1, 1) BETWEEN 'A' AND...
Parameters that can alter a node’s results. After adjusting a parameter, the rescan command must be applied to that node and all nodes above it. There is a moderately intelligent scheme to avoid rescanning nodes unnecessarily (for example, Sort does not rescan its input if no parameters of...
Without specifying how the computer should proceed to get the results. It is the DBMS that must find “how” to perform the operation by ensuring: Return the right result Ideally, as soon as possible “As soon as possible” means: Minimize disk access Give priority to sequential readings (...
Which chart: postgresql-ha 3.2.1 Describe the bug Somehow both Postgres Instances End up in Primary Mode. This Results in pgpool redirecting requests to both instances and thus the 2 Databases drift appart with different States. Output o...