Postgres is a very good open-source database. Good performance.
When it comes to databases, there's the topic of backup and import.
Backups are also broken down in a number of ways.
1. Full backup
This is the way most people use it to back up the entire database, including all database objects, such as user tables, system tables, indexes, views, and stored procedures. But it takes more time and space, so it's generally recommended to do a full backup
Postgres can not be directly accessed between different databases, such as database Test1 and test2, each database has a table of TableA; I am using the operating system Win8.1,postgres version 9.3.6; Access to Postgres using the PGADMINIII tool; Create a TableA in two databases (TEST1,TEST2) respectively; Test1 database creates TableA and inserts data: CREATE T
Php page access to IPVs database problems the local machine is equipped with php, apache, postgres database nbsp; I want to insert the data in the page from the browser php page to the local database, the code I wrote must be correct, but it means that the data cannot be inserted into the database (during the runtime, he only runs the code before the database code is connected, and then does not leave, and no error is reported, but the code is absolu
in the CREATESTMT structure, and then control whether or not to create a table or make an error message.Get the current user name as followsDatumcurrent_user (Pg_function_args) {pg_return_datum (DirectFunctionCall1 (Namein, Cstringgetdatum ( Getusernamefromid (GetUserId ()))));}This function is the intrinsic function of the PG, using the effect:postgres=# Select Current_User; Current_User--------------Postgres (1 row)In this way, you can complete the
Uber engineers on the official blog have described why they switched from Postgres to MySQL database . Uber's early architecture was made up of back-end applications written by Python, using the Postgres database. Since then, Uber's architecture has changed dramatically, transforming to microservices models and new data platforms. Previously they used Postgres, a
Summary of Postgres operations in Ubuntu
1.Basic operation commands
After the installation is complete, PostgreSQL creates a database user account named Postgres by default. It is a super Administrator account like the root account of MySQL and the SA account of sqlserver, but unlike MySQL, postgreSQL also created a Unix account named S.
Like the master database of sqlserver, the default database o
This is a creation in
Article, where the information may have evolved or changed.
Github.com/lib/pq
PG is a pure go write driver of the Postgres database. The author gave us a little joke, the PQ will always be habitually written PG there is no ... The installation method is as follows:
go get github.com/lib/pq
Register
As mentioned earlier, driver needs to call Sql.register to register the Driver.driver type interface driver implementation by name. T
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
Function Introduction
POSTGRES-XC/XL/X2 is an open source project. It provides a multiple-master synchronous, transparent, PostgreSQL cluster solution. Unlike other cluster tools, it has a strong scalability when writing data, and introduces the concept of cluster environment with multiple master architectures. Multi-master means that when writing data, it is no longer subject to a single master node and will be well improved in writing speed.
: maxspeed:winter=* means the maximum speed limit in winter
Postgressql Database Installation
Open source free database: PostgreSQL Download Installation Tutorial _ Baidu Experience OSM data Extraction
Download Osm:http://dev.openstreetmap.org/~bretth/osmosis-build/osmosis-latest.zipdownload China map dataHttp://download.geofabrik.de/asia/china.html
Data cropping
Regional cut, cut the map of China into Wuhan map:
Osmosis--READ-PBF file= "CHINA-LATEST.OSM.PBF"--used-node--bounding-box left=113.9
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
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