: There are various types of xlog records (for example, Heap,btree,clog,storage,gin, and Standby records, just to name a few).Xlog Records Backward links. This way, each entry points to the previous entry in the file. In this way, we can fully believe that we have found the end of the record as long as we want to point to the pointer to the previous entry.make XLOG with certaintyAs you can see, a change could trigger many xlog entries. This is true for all kinds of statements, such as a large DE
dedicated database management tool (such as SQLite's SQLite Expert, PostgreSQL pg Admin, MySQL, phpMyAdmin, etc.), directly within the IDE to view. Eric6 comes with a built-in SQL browser, the interface is relatively simple, and each time the opening must be reset, not convenient. Pycharm is a database Tools and SQL plug-in to enable the connection and view of the databases, to temporarily view the data is
PostgreSQL tutorial (13): database management details, postgresql details
I. Overview:
A database can be considered as a name set of an SQL object (database object). Generally, each database object (table, function, etc.) belongs to only one database. However, for some system tables, such as pg_database, it belongs to the entire cluster. More accurately, a database is a set of patterns, and a schema contain
Introduction to Interfaces
IDE interface
(Integrated-drive-electronics) is now commonly used external interface, mainly connected to the hard disk and optical drive. Using 16-bit data parallel transmission mode, small size, fast data transmission. An IDE interface can only receive two external devices.
The IDE's English is all called "Integrated Drive Electronics", or "Electronic integrated
PostgreSQL tutorial (18): client commands (2), postgresql tutorial
VII. pg_dump:
Pg_dump is a tool used to back up PostgreSQL databases. It can even perform a full and consistent backup when the database is being used concurrently without blocking access to the database by other users. The dump format generated by this tool can be divided into two types: script a
Manual PostgreSQL database initialization tutorial in windows, initialize postgresql
Environment: win7 64 sp1PG: 9.3.5
1. Create the postgres user, and the password is also postgres:
net user postgres postgres /add
2. Create a data directory under the root directory of the database:
C:\Program Files\PostgreSQL\9.3>md data
3. Remove the administrator permission on
Tutorial on installing and using the extension module on PostgreSQL, postgresql extension module
Installation Module
Note: My runtime environments are Ubuntu 10.04 and PostgreSQL 8.4.
First, install the postgresql-contrib package and restart the database server. Then, check the contrib directory to see if there are som
PostgreSQL tutorial (1): Detailed description of data tables and detailed description of postgresql
I. Table definition:
For any relational database, tables are the core and basic object units of data storage. Now let's start from here.1. Create a table:Copy codeThe Code is as follows:Create table products (Product_no integer,Name text,Price numeric);2. delete a table:Copy codeThe Code is as follows:Drop ta
PostgreSQL tutorial (14): database maintenance, postgresql tutorial
I. Disk Space Restoration:
In PostgreSQL, the data rows deleted or updated using the delete and update statements are not actually deleted, the physical address of the old data row sets the row status to deleted or expired. Therefore, when data in a data table changes frequently, the space occupi
PostgreSQL replication cluster overview, PostgreSQL replication Cluster
For pg replication, high availability, and load balancing clusters, write an overview for future reference.
Pg has the following various replication-Based Cluster solutions, most of which were used, and some were not sorted out at the time. There are also many cluster configuration documents on the Internet. After this document, find a
Mac installs PostgreSQL by default, so that PostgreSQL can be accessed remotelyMac default PostgreSQL directory storage path is /usr/local/var/postgres/ in this directory, modify two files, one is postgresql.conf, one is pg_ Hba.conf, and finally a reboot.Modify Postresql.conflisten_addresses = ' * ' # Modify the configuration here to allow link
Postgresql C/C ++ API and postgresql sqlapi
1. postgresql learning uri recommendation
http://www.php100.com/manual/PostgreSQL8/ http://www.php100.com/manual/PostgreSQL8/reference.html http://www.yiibai.com/html/postgresql/
[Note tips byRuiy, distinguish uri/url, service/server,There has a certain truthChillax!]
Frie
2.4 Adjusting checkpoints and xlogSo far, this chapter has provided insight into how PostgreSQL writes data, in general, what Xlog is used for. Given this knowledge, we can now continue and learn what we can do to make our databases work more efficiently in both replication and single-server operations.2.4.1 Understanding CheckpointsIn this chapter, we have seen that it has been written to Xlog before the data can be elsewhere. The problem is that if
PostgreSQL tutorial (10): Performance Improvement tips and postgresql Performance Improvement
1. Use EXPLAIN:
PostgreSQL generates a query plan for each query, because selecting the correct query path has a critical impact on performance. PostgreSQL itself contains a scheduler for optimal planning. We can use the EXPLA
Detailed description of the PostgreSQL Partition Table (partitioning) application instance, postgresql Partition Table
Preface
Vertical table sharding is required in the project, that is, data is split into n tables according to the time interval. PostgreSQL provides the partition table function. A partition table actually Splits a large logical table into severa
Label:2.2 Xlog and ReplicationIn this chapter, you have learned that the transaction log for PostgreSQL has made all changes to the database. The transaction log itself is packaged as an easy-to-use 16MB segment.The idea of using this change set to replicate data is not farfetched. In fact, this is a logical step in the development of each relational (or even non-relational) database system. Other parts of the book, you will see in many ways how the
Label:Brief introduction We can manage the PostgreSQL database through some graphical interface management programs, such as Pgadmin, to create new objects by visual or command line, delete and edit existing objects (such as directories, schemas, tables, etc.) and access them through JDBC or ODBC. Interface operation: To open a connection to a service, select the desired service in the tree, double-click it, or use the Connect on the Tools menu.In the
In the previous chapters, we have understood the various replication concepts. This is not just a theoretical overview of the things that will enhance your consciousness for the next thing to be introduced, but will also introduce you to a broad topic.In this chapter, we will be closer to the actual solution and understand how PostgreSQL works internally and what replication means. We'll see what the so-called transaction log (XLOG) does, and how it w
PostgreSQL tutorial (8): Index details, postgresql Index
I. Index type:
PostgreSQL provides multiple index types: B-Tree, Hash, GiST, and GIN. Because they use different algorithms, each index type has a suitable Query type, the create index Command creates a B-Tree INDEX.1. B-Tree:Copy codeThe Code is as follows:Create table test1 (Id integer,Content varchar);Cr
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