[英]How to improve add column query from large table using python psycopg2
I am using following command to add the new column in existing large table in postgresql. 我正在使用以下命令在postgresql的现有大表中添加新列。
alter table table_name add column column_name bigserial
Is there any way to increase the performance of above query on large table? 有什么方法可以提高大型表的上述查询性能?
to reduce lock time, you can: 为了减少锁定时间,您可以:
alter table table_name add column column_name bigint;
create sequence seq_name;
with c as (select * from table_name)
update table_name set column_name = nextval('seq_name'::regclass);
alter table table_name alter column column_name set default nextval('seq_name');
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