S skills, Postgres skills
If you need to add indexes when the business volume is large, you need to use CONCURRENTLY. Otherwise, your database will easily break down.
For example
create index CONCURRENTLY idx_order_records_bank_statist_uid on order_records(statist_uid)
See
Http://www.postgresql.org/docs/9.1/static/sql-createindex.html
In a large business volume, if you want to execute some time-consuming database tasks, sometimes you will fin
PHP page access to postgres database issues
This machine is equipped with Php,apache,postgres database
I want to insert the data from the page into the native database from the browser PHP page, I write the code is certainly correct, but just can't insert the data into the library (run, he only run the code before the library code, and then do not go, and no error, but the code is absolutely correct, the fo
Postgres-XL: PostgreSQL-based open-source scalable Database Cluster,Postgres-XL: PostgreSQL-based open-source scalable Database ClusterIn the past year, IOE has become more and more popular in the industry. Many traditional enterprises have also placed their "IOE" plans on their desktops. I have always wondered why these non-Internet companies (such as banks) are motivated to do this? The empty slogans such
One: Command line Backup and recovery Postgres database①: First switch to Postgres userSu Postgres
②: Backing up a database named host to a temporary file Host.dumpPg_dump-w Host >/tmp/host.dump
③: Import data from backup file infile to database named dbnamePsql dbname
Second: Update a data record in a datasheet①: Log in to the database as a
Rails connection postgresql error: psql: Fatal error: User "s" Ident authentication failed, psqlpostgresPsql: Fatal error: User "s" Ident authentication failed
1. After the postgresql database is installed, you must initialize and configure some rails projects to connect to postgresql.
After postgresql data is installed (the yum command is directly installed)
Step 1: Initialize the database
# Service postgresql initdb
(Note: After initialization, the default postgresql database has a default us
1. sudo apt-get install PostgreSQL #安装psql2. Su passwd postgres #设置postgres账户的密码3. postgresql.conf sets the value of the Listen_addresses key in the file to4. pg_hba.conf the configuration file, add the following configuration under the host all 127.0.0.1/32 MD5 lineHost All 0.0.0.0/0 MD55. The above configuration file is installed by default under/etc/postgresql/9.4/main6.Sudo/etc/init.d/postgresql start #
field type in the table. 4.Extract procedures/functions/packages[[emailprotected]_222 ~]# ora2pg-c/etc/ora2pg/ora2pg.conf[========================>] 2/2 functions (100.0 %) end of output. [[emailprotected]_222 ~]# cat lottu04.sql--Generated by ORA2PG, the Oracle database Schema Converter, version 17.4- -Copyright 2000-2016 Gilles darold. All rights reserved.--DATASOURCE:dbi:Oracle:ora229SET client_encoding to ' UTF8 '; \set on_error_stop ONCREATE OR REPLACE F Unction ora2pg_16_to10 (v_16_data t
Operating environment for Kali virtual machines
1
[Email protected]:~# apt-get Install PostgreSQL
Start the service
12
[Email protected]:~# service PostgreSQL start[OK] starting PostgreSQL 9.1 database Server:main.
Modify the PostgreSQL password to Toor:
123
[Email protected]:~# sudo-u postgres psql postgrespostgres=# alter user p
Data conversion in the S database and postgres Data Conversion
After s8.3, the default conversion between field data is canceled. If you need to perform data transformation, you can use ":" in the S database to convert the field data type. Actually, ":" is called.CAST function.Which fields can be converted into one another?
You only need to study the cast function to obtain the answer to this question. The cast function information is managed in the
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 primary key (PID));
Notice:create table/primary KEY would CREATE implicit index "ZHONGWC_PI
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 Backup_user; GRANT SELECT on all TABLES in the
Aggregate functions do not need to appear in group. However, for a direct select field, Postgres requires the group by field. Some databases do not need this field, such as SQL lite.
2. Postgres's replacement for the decode function in Oracle: case when .....
3. Type values such as flag are directly stored as int in dB, and the bitwise AND operator of S can be directly calculated.
4. Count (expr) If expr is a Boolean value, count will be misused.
Inc
Mysql, sqlsever, oracle, redis, mongo, postgres and other database backup and recovery commands, sqlseverredis
The following is a simple example of how to back up and restore each database. For more detailed parameters and configurations, refer to relevant information.
I. mysql:
Parameter description:
$ User
$ Password
$ Targethost
$ Port
$ Charset
$ Dbname
$ Table
$ Filename
User Name
Password
Ip (localho
This is a creation in
Article, where the information may have evolved or changed. "' Gopackage mainimport (" FMT "" Log "" Time "" Github.com/go-xorm/xorm "_" GITHUB.COM/LIB/PQ ") var engine *xorm. Enginefunc Main () {}func init () {psqlinfo: = FMT. Sprintf ("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", "127.0.0.1", 5432, "Postgres", "12345678", " Postgres ") var err errorengine, err = X
First, IntroductionJSON is a full copy of the input, and then parse it, so it preserves the input spaces, repetition keys, and order. The JSONB is a binary that is saved after parsing the input, and it removes unnecessary spaces and duplicate keys when parsing, and the order and input may not be the same. Make time without parsing again.Summarize:
.
JSON
jsonb
Save
Fast
Slow
Take
Slow
Fast
Ii. Practice
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