PostgreSQL is similar to Oracle's multi-process framework, so it can support high-concurrency application scenarios. This is similar to Oracle databases, so it is easier to switch Oracle DBA to PostgreSQL databases, after all, PostgreSQL databases are similar to Oracle databases.
At the same time, the source code of the Post
Comparison of Oracle, mysql, sqlserver, and postgresql statements, postgresql and oracle
1. Paging
Oracle:SELECT * FROM (select a. *, rownum rn from (select T. * from sj_receiptinfo t WHERE t. taxno like concat ('%', CONCAT (?, '%') Order by t. id desc) a where rownum
Mysql:Select * from tableName where ConditionLimit (Current page number * Page capacity-1),Page size pagesize
SqlServer: SELECT w2.n, w1.
PostgreSQL tutorial (16): System View Details, postgresql View
I. pg_tables:
This view provides access to useful information about each table in the database.
Name
Type
Reference
Description
Schemaname
Name
Pg_namespace.nspname
The schema name of the table.
Tablename
Name
Pg_class.relname
Table name.
Tableowner
Name
Five tips for Instagram to improve PostgreSQL performance, postgresql Performance Optimization
As Instagram grows, Postgres continues to serve as a solid foundation for Instagram and stores a vast majority of user data. Less than a year ago, we also wrote on our blog that Instagram "stores a large amount of data" and adds 90 pieces of data per second. Now, this data has increased to 10000 pieces of peak dat
PostgreSQL recursive query for tree structure query and postgresql Recursion
A very interesting feature found during Postgresql's use is that recursive queries can be used for results that require a tree-like structure. For example, the data structure of common company departments is similar to the following SQL statement when we design the table structure. If parent_id is NULL, it indicates the top-level
The example of this paper describes the Base64 encryption, MD5 encryption and SHA1 encryption implemented by JS. Share to everyone for your reference, specific as follows:
1, Base64 encryption
The Base64.js file is introduced into the page, and the method is called:
2, MD5
PHP connection and operation of PostgreSQL database method, PostgreSQL database
This article describes the PHP connection and operation of the PostgreSQL database method. Share to everyone for your reference.
The implementation method is as follows:
Copy the Code code as follows:$PG = @pg_connect ("Host=localhost user=postgres password=sa Dbname=employes")Or Die
PHP encryption and decryption function and DES encryption and decryption instance, phpdes encryption and decryption instance
This article describes the application of the encryption and decryption function in PHP and DES encryption and decryption, and shares it with you for
manages authentication at the database level. Basic only supports password authentication.
PostgreSQL supports a wide range of authentication methods: Trust authentication, password authentication, Kerberos authentication, Ident based authentication, LDAP authentication, PAM authentication
Encryption
You can specify a password at the table level to encrypt the data. You can also us
PHP, and phpdes. PHP encryption and decryption functions and DES encryption and decryption instances. phpdes encryption and decryption instances this article describes the application of the encryption and decryption functions in PHP and DES encryption and decryption. PHP
An example is provided to briefly introduce arrays in PostgreSQL and postgresql.
PostgreSQL has many out-of-the-box data types, from standard digital data types, to geometric types, and even network data types. Although many people ignore these data types, they are one of my favorite features. The array data type, as you expected, can be used to store array data
Basic PostgreSQL commands and PostgreSQL commands
1. Change the table name
Alter table name rename to new table name
2. Change the field name
Alter table name rename field name to new field name
3. Change the field type.
For example, the original type of the ID field is character varying (50) and the new type is integer.
Where, the ID contains numbers such as 1, 2, and 3.
Use the following statement to cha
1. Download
To the website to download the latest PostgreSQL Studio, I downloaded pgstudio_1.2-bin. zip because there are no Tomcat in my computer.
If the computer has a good configuration of tomcat, you can download Pgstudio_1.2.zip, after decompression is a war package.
Download Address: http://www.postgresqlstudio.org/download/
2. Decompression
Unzip the compressed file to see the following directory:
3. Run
Run in Bin directory:
./catal
Oracle defines the DES encryption and decryption and MD5 encryption function example, des encryption and decryption
(1) DES encryption function
create or replace functionencrypt_des(p_text varchar2, p_key varchar2) return varchar2 isv_text varchar2(4000);v_enc varchar2(4000);raw_input RAW(128) ;key_input RAW(128) ;decr
PostgreSQL date calculation functions, postgresql Functions
I. connector in each data
SqlServer connector: + (plus sign)
Sqlite connector:. (point)
PostgreSQL connector: | (OR)
II:
Today, when I was computing data in PostgreSQL, I had to record a few materials ~!
Functions and variables used
To_char (), Date (), now ()
Enable postgresql remote permissions and enable postgresql
Preface: Previously, only the remote permission of the specified IP address of postgresql will be configured. Later, a client wants to remotely connect to postgre and view data, but her IP address changes frequently, as a result, I had to re-set the settings every time, and finally found the method. Now
Label:In the process of reading any questions, welcome to communicate togetherEmail:[email protected]qq:1494713801One, PostgreSQL time type conversion--The time type is converted into character type select To_char (current_date, ' yyyy/mm/dd '); select To_char (current_date, ' yyyy-mm-dd '); select To_char (now (), ' yyyy-mm-dd '); select To_char (Current_timestamp, ' HH:MI:SS '); select To_char (Current_timestamp, ' yyyy/ Mm/dd HH:MI:SS '); --The str
Label:Objective:Recently do data synchronization, need to get data from PostgreSQL, found that once the data is more, then the speed of reading is very slow, and memory consumption is very much GC not fall.Code Sample:In order to facilitate the explanation, the following writing the case code, from B2c_order to obtain data, this data table about 6G. Package Com.synchro;
Import java.sql.*;
/**
* Created by Qiu.li on 2015/10/16.
*
/public class Test
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