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AURORA POSTGRESQL XLOG ARCHIVE
AURORA POSTGRESQL XLOG WINDOWS

The logical and physical structures of the WAL (transaction log).

In the subsequent sections, the following topics are described: In the first section, the overall picture of the WAL has been provided, introducing some important concepts and keywords. So the complete explanation of WAL in PostgreSQL is made as follows. It also made possible the implementation of the Point-in-Time Recovery (PITR) and Streaming Replication (SR), both of which are described in Chapter 10 and Chapter 11 respectively.Īlthough understanding of the WAL mechanism is essential for system integrations and administrations using PostgreSQL, the complexity of this mechanism makes it impossible to summarize its description in brief. The WAL mechanism was first implemented in version 7.1 to mitigate the impacts of server crashes. Though this is a little confusing, in this document the PostgreSQL definition has been adopted. There the term is used as synonym of transaction log, and also used to refer to an implemented mechanism related to writing action to a transaction log (WAL).

In the field of computer science, WAL is an acronym of Write Ahead Logging, which is a protocol or a rule to write both changes and actions into a transaction log, whereas in PostgreSQL, WAL is an acronym of Write Ahead Log. As the log contains sufficient information about each transaction executed already, the database server should be able to recover the database cluster by replaying changes and actions in the transaction log in case of the server crash. It is a history log of all changes and actions in a database system so as to ensure that no data has been lost due to failures, such as a power failure, or some other server failure that causes the server crash. Transaction log is an essential part of database, because all of the database management system is required not to lose any data even when a system failure occurs.

11.4 Detecting Failures of Standby Servers.

11.3 Managing More Than One Standby Server.

11.1 Starting the Streaming Replication.

10.4 Point-in-Time Recovery with Timeline History File.

10.3 timelineId and Timeline History File.

AURORA POSTGRESQL XLOG ARCHIVE

9.10 Continuous Archiving and Archive Logs.9.2 Transaction Log and WAL Segment Files.Heap Only Tuple (HOT) and Index-Only Scans 5.3 Inserting, Deleting, and Updating Tuples.Foreign Data Wrappers (FDW) and Parallel Query 3.6 Creating the Plan Tree of Multiple-Table Query.3.3 Creating the Plan Tree of a Single-Table Query.3.2 Cost Estimation in Single-Table Query.1.4 The Methods of Writing and Reading Tuples.1.3 Internal Layout of a Heap Table File.1.2 Physical Structure of Database cluster.1.1 Logical Structure of Database cluster.

If more information is required, I'll be glad to provide it. If anyone can tell me what I'm doing wrong, I would be very grateful. My xlog folder downsized to 50 files (800 mb), not anywhere near the 200 mb limit I set in the config.

AURORA POSTGRESQL XLOG WINDOWS

I then forced checkpoints through SQL, vacuumed the database, restarted the windows service and tried pg_archivecleanup, nothing really worked. I can see the properties have been set correctly when I query pg_settings. To reduce the size of the folder, I tried setting wal_keep_segments to 0 or 1, setting the max_wal_size to 200mb, reducing the checkpoint_timeout, setting archive_mode off and archive_command to an empty string. After the script is done, the database structure is fine, the data is there but the xlog folder already contains 55 files (880 mb). It executes initdb, registers a windows service, starts it, creates an empty database and restores a dump into the database. I wrote an setup script for my Postgresql 9.6 service instance. I've read a lot of threads about this issue or similar ones but nothing I've tried helped. I'm trying to configure a PostgreSQL 9.6 database to limit the size of the pg_xlog folder.