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Computer information system Definition: data intensive, man-machine interactive computer system with the main purpose of providing information services Features: large quantity, lasting, sharing and providing a variety of services Structure: 1,Resource Management(DBMS and DB All on this layer) Various data information and resource manage ...

This article introduces PostgreSQL materialized views, which are used to store physical query results and can be updated periodically. A view is a virtual table of the underlying physical table, which itself does not save data. In order to distinguish it from the simple view, the underlying table data can also be updated through the view by d ...

2021SC@SDUSC summary PostgreSQL code I am responsible for: query compilation and execution Analysis content of this blog: Query Optimization - generate plan The whole process of query optimization can be divided into three stages: preprocessing, generating path and generating plan. In the last blog, I analyzed the process of generating the ...

Get previous and next business day practiceprefaceIn fact, this article has been published and discussed before. In the previous article, I introduced how to build a working day table through the sql statement of postgresql database, and how to use sql syntax to obtain the working day or natural day of a certain day, but I found that many detai ...

PostgerSQL object identifier OID OID is an identifier used in PostgreSQL to identify database objects (database, table * *, view, * * stored procedure, etc.), which is represented by an unsigned integer of 4 bytes. It is the primary key of most system tables in PostgreSQL. Type oid represents an object identifier. There are also alias types ...

Create relevant views according to the data dictionary to facilitate query create schema dba; create view dba.ro_conflicts as select datname,pg_stat_get_db_conflict_all(oid) conflict_all,pg_stat_get_db_conflict_bufferpin(oid) conflict_bufferpin,pg_stat_get_db_conflict_lock(oid) conflict_lock,pg_stat_get_db_conflict_snapshot(oid) conflict_ ...

8. TopoGeometry constructor 8.1. CreateTopoGeom CreateTopoGeom - from the array of topological elements tg_type: 1:[multi]point, 2:[multi]line,3:[multi]poly, 4:collection creates a new topological geometry object 8.1. 1. Summary topogeometry CreateTopoGeom(varchar toponame, integer tg_type, integer layer_id, topoelementarray tg_objs); topog ...

4. Topology constructor 4.1. CreateTopology CreateTopology - create a new topology schema and register the new schema in the topology. Topology table. 4.1. 1. Summary integer CreateTopology(varchar topology_schema_name); integer CreateTopology(varchar topology_schema_name, integer srid); integer CreateTopology(varchar topology_schema_name, ...

3. Topology and topology geometry management 3.1. AddTopoGeometryColumn AddTopoGeometryColumn - adds a topology geometry column to the existing table and registers the new column as a layer in the topology. And return to the new layer_id. 3.1. 1. Summary integer AddTopoGeometryColumn(varchar topology_name, varchar schema_name, varchar tabl ...

PostgreSQL is the most open source database like oracle. We can compare Oracle and learn its architecture, which is easier to understand. The main structure of PostgreSQL is as follows: 1. Storage structure PG data storage structure is divided into logical storage structure and physical storage structure. Among them: logical storage structur ...