INFORMATION_SCHEMA provides access to database metadata, information about the MySQL server such as the name of a database or table, the data type of a column, or access privileges.Other terms that are sometimes used for this information are data dictionary and system catalog. TABLE_SCHEMA: nvarchar(128) Name of schema that contains the table. Information Schema PROFILING Table Statement resource usage Information Schema QUERY_CACHE_INFO Table View the contents of the query cache. The information schema in a relational database is a separate table that documents information about the database itself. TABLES Queries. SYSOBJECTS versus TABLES View Most RDBMSs support the majority of INFORMATION_SCHEMA views, and each view exposes essentially identical information regardless of the vendor. In relational databases, the information schema (information_schema) is an ANSI-standard set of read-only views that provide information about all of the tables, views, columns, and procedures in a database. Rob Gravelle provides an overview of the INFORMATION_SCHEMA database as well as some practical examples of its many uses. It is a built-in virtual database with the sole purpose of providing information about the database system itself. Beside the table names, you can also retrieve their type (base table or view) and engine: SELECT table_name, table_type, engine FROM information_schema.tables WHERE table_schema = 'sakila' ORDER BY table… INFORMATION_SCHEMA is an ANSI standard set of metadata of your database objects and you should really get in the habit of using it only if you plan to be porting your objects (tables, views, etc) between different types of databases like Oracle, DB2, MySQL, etc. c) using the information_schema tables, as the linked question: select table_rows from information_schema.tables where table_schema = 'database_name' and table_name = 'table_name' ; Accuracy: Only an approximation. information_schema is the database where the information about all the other databases is kept, for example, names of a database or a table, the data type of columns, access privileges, etc. Although the name of this view is TABLES, views are also listed. The information schema is defined in the SQL standard and can therefore be expected to be portable and remain stable — unlike the system catalogs, which are specific to PostgreSQL and are modeled after implementation concerns. The information_schema.columns catalog contains the information on columns of all tables. For more information, see Flat-rate pricing . The table_catalog field is just going to tell us what database we're in.The table_schema field, however, tells us the owner, and of course, the table_type tells us whether or not we've got a regular table or a view on our hands. The information schema (INFORMATION_SCHEMA) is a standard representation of metadata in SQL.Historically, each developer of relational DBMS provided system tables that contained meta-information in particular names of tables, columns, data types, constraints, etc. From MariaDB 10.3.5:. In this example each schema and the number of tables and views defined within them are listed: INFORMATION_SCHEMA.TABLES or INFORMATION_SCHEMA.COLUMNS work for only specified databases. Tables. The INFORMATION_SCHEMA.COLUMNS view allows you to get information about all columns for all tables and views within a database. Structure of system tables can be changed between versions of the product. For example, the following query identifies all of the tables and views that Drill can access: Use the INFORMATION_SCHEMA.TABLES view to do this. For projects that use flat-rate pricing, queries against INFORMATION_SCHEMA views and tables consume your purchased BigQuery slots. u.table_schema, u.table_name, u.column_name from information_schema.key_column_usage u inner join information_schema.table_constraints c on u.constraint_name = c.constraint_name where c.constraint_type = ‘foreign key’ update @table set primarykeyconstraintname = unique_constraint_name from @table t inner join information_schema… The information_schema database is a virtual database that MySQL uses to store information about your databases and other settings. Queries against this view must have a dataset or region qualifier.-- Returns metadata for … Let us see a quick demonstration of the same. It gets a list of all MyISAM tables from the information_schema and for each table does a select count(*) into @discard from database.table. Information schema views enable applications to work correctly although significant changes have been made to the underlying system tables.” We will be using a couple of the views in the information schema in order to run queries that help determine the makeup of tables in the data source. 2) PostgreSQL DESCRIBE TABLE using information_schema. TABLES View¶ This Information Schema view displays a row for each table and view in the specified (or current) database, including the views in the INFORMATION_SCHEMA schema itself. The INFORMATION_SCHEMA database is where each MySQL instance stores information about all the other databases that the MySQL server maintains. INFORMATION_SCHEMA views only represent a subset of the metadata of an object. The information schema consists of a set of views that contain information about the objects defined in the current database. If the table is the target of frequent inserts and deletes, the result can be way off the actual count. TABLES is a reserved word in Drill and requires back ticks (`). prrao, There is no difference in how the table is created in either one, the difference is how you are testing the table's existence. SELECT TABLE_SCHEMA, Count(TABLE_SCHEMA) FROM AdventureWorks2012_Data.INFORMATION_SCHEMA.TABLES GROUP BY TABLE_SCHEMA SQL Server Catalog Views. INFORMATION_SCHEMA.Tables is pretty straight forward in the information it reports back. Run an INFORMATION_SCHEMA.`TABLES`query to view all of the tables and views within a database. However, the TABLE_SCHEMA value for them is INFORMATION_SCHEMA. The INFORMATION_SCHEMA set of views are the ANSI/ISO standard catalogs for metadata. This query returns both base tables as well as views. Like most relational databases, MySQL provides useful metadata about the database itself. Other terms that sometimes are used for this information are data dictionary and system catalog.. INFORMATION_SCHEMA is the information database, the place that stores information about all the … This background information is about many different aspects of the relational database; includes data about tables, rows, columns and … About the information_schema database.