postgres create index

1. Prepare Create a base table first: CREATE TABLE mytb1 (ID serial,name character varying,age integer);To create an index on the name field: Create INDEX Mytb1_name_index on MYTB1 (name); To view the MYTB1 table structure:

Reference: http://my.oschina.net/dddpeter/blog/116153 1. Create a user 1 Sudo-s-U postgres 2 Psql 3 postgres# CREATE USER xxxx1 with PASSWORD ' xxxx '; 4 postgres#

with SQL commands \? For help with Psql commands \g or terminate with semicolon to execute query \q to quit Zwcdb=> Create a table[Plain]View Plaincopyprint? [Email protected] data]$ psql-u zhongwc-d zwcdb-h 192.168.1.203-p 1521 Password for user zhongwc: Psql (9.2.2) Type ' help ' for help. Zwcdb=> CREATE TABLE T_ZHONGWC (PID integer,pname varchar (+), constraint ZHONGWC_PID_PK pri

Tags: handle toe test connect ant Import Export command exp GREWhat this article contains: Use commands to manipulate import and export of Oracle, Postgres, MySQL, including logging on to dataNote: I am using the Center OS operating system in the company, so both Oracle and Postgres are used in Linux and not tested in other tools, and MySQL is used on its own laptops, both under Linux and DOS commands.1.Ora

CREATE USER backup_user with ENCRYPTED PASSWORD ' qux94874 '; GRANT CONNECT on DATABASE foo_db to Backup_user; GRANT CONNECT on the DATABASE bar_db to backup_user;\c foogrant USAGE on the SCHEMA public to Backup_user; GRANT SELECT on all sequences in the SCHEMA public to Backup_user; GRANT SELECT on all TABLES the schema public to backup_user;\c Bargrant USAGE on the schema public to Backup_user; GRANT SELECT on all sequences in the SCHEMA public to B

This article mainly summarizes the MySQL index operation methods, including creating indexes, rebuilding indexes, querying indexes, and deleting indexes. In the following example, 'table _ name' indicates the data table name, 'index _ name' indicates the index name, and column list indicates the Field list (for example, 'id ', 'order _ id '). 1.

1. CREATE index The creation of the index can be done in the CREATE TABLE statement, or you can add indexes to the table separately with the CREATE INDEX or ALTER TABLE. The following command statements show how to

Tags: except composite index end use key read-write min causes the specifiedFirst, insert two records into the Users collection, and then use the Users collection for a demonstration of index management:> user1={"name":"liming","age":20,"gender":"F"}{ "name" : "liming", "age" : 20, "gender" : "F" }> db.users.insert(user1)WriteResult({ "nInserted" : 1 })> user2={"name":"zhangsan","age":25,"gender":"F"}{ "nam

row from the table T1 to see the data that this row contains.(2) Use the Index on table T2 to directly locate the row in the T2 that matches the value of T1. Similarly, use the index on table T3 to directly locate rows in T3 that match the values from T1.(3) Scan the next line of the table T1 and repeat the previous procedure until all the rows in the T1 are traversed.In this case, a full scan is still per

,Indexing also increases processing overhead for insert, delete, and update operations. In addition, too many composite indexes, in the case of a single field index,In general, there is no value, on the contrary, it will reduce the performance of the data to increase the deletion, especially for frequently updated tables, the negative impact is greater. 2. Create an in