postgres=# \d+ example_tbl Table "public.example_tbl"Column | Type | Collation | Nullable | Default | Storage | Compression | Stats target | Description---+---+---+---+---+---+---+---+---id | integer | | not null | | plain | ...
In PostgreSQL, built-in functions like pg_database_size(), and pg_relation_size() are used to get the database and table size respectively. The pg_size_pretty() function can be used with the collaboration of the pg_database_size(), pg_relation_size() to present the database/table si...
通过SQL查表的空间大小: SELECT relname, age(relfrozenxid) as xid_age, pg_size_pretty(pg_table_size(oid)) as table_size,reltuples as rowCounts FROM pg_class WHERE relkind = 'r' ORDER BY pg_table_size(oid) DESC; 会看到某些更新频繁的表的table_size会非常大,但实际的数据是很少的。表的...
in which case raising the request size or reconfiguring SHMMIN is called for. The PostgreSQL documentation contains more information about shared memory configuration. child process exited with exit code 1 类似地,使用pg_ctl命令启动PostgreSQL服务器时也会出现错误。 DETAIL: Failed system call was shmget...
主要针对VACUUM,CREATE INDEX,ALTER TABLE ADD FOREIGN KEY等操作。 在对整个数据库进行VACUUM或者较大的index进行重建时,适当的调整该参数非常必要。 PostreSQL文档提示在启用了autoacuum功能的情况下,该参数不能配置的过大。 四.SGA内存 shared_buffers ---共享缓冲区 ...
select pg_relation_size(); select pg_table_size(); select pg_total_relation_size(); 物理、逻辑复制槽: pg_create/drop_physical_replication_slot(slotname); pg_create_logical_replication_slot(slotname,decodingname); pg_logical_slot_get_changes();...
(MemoryContext context,void*pointer,Size size);//重分配内存void(*init)(MemoryContext context);//初始化内存上下文void(*reset)(MemoryContext context);//重置内存上下文void(*delete)(MemoryContext context);//删除内存上下文Size(*get_chunk_space)(MemoryContext context,void*pointer);//检查内存片段的大小...
一般来说可以使用hash table中的一个PagetableEntry用来存储一个page中哪些tid是符合查询需求的，block no对应 page number, PagetableEntry中bitmap words的第n bit代表page中第n+1个tuple。这样当我们构建bitmap时，相同block no的tid会被聚合到同一个key对应PagetableEntry中，btgetbitmap扫描完成所有存在的TID...
model(tablename, schema = null) 返回Model实例去执行SQL。 transaction(callback, schema) 事务执行,其内部是调用了Model实例的transaction。 复杂查询 letpqorm = initORM(dbconfig); ;(async() =>{letcond = {is_delete:0,nickname: {'ILIKE':'%ae%'} ...
select pg_size_pretty(pg_tablespace_size('pg_default')); select pg_size_pretty(pg_relation_size('account_move_line')); select sum(t.size) from ( SELECT table_schema || '.' || table_name AS table_full_name, pg_total_relation_size('"' || table_schema || '"."' || table_name...