Questions tagged [write-ahead-logging]
Write-Ahead Logging (WAL) is a standard method for ensuring data integrity.
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WAL record action code dictionary
I'm exploring the module wal2json for the first time. I've set up the replication slot using the ReadMe examples.
When peeking the replication slot, every data value begins with an "action" ...
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Ensure WAL Ordering on Write
Let’s say I have 3 rows: A, B and C.
Using debezium, which reads from the WAL and publishes messages to Kafka, I would like to re-produce the 3 rows to the WAL in order using a single txn.
Postgresql ...
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Understanding WAL LSN
I’m using CNPG Postgres with 2 node availability. There’s a primary and secondary. The primary uses synchronous replication. I am using Change Data Capture with debezium. It creates a replication slot,...
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wal-g/postgresql: How to turn continuous into punctual backups for sparsifying archival?
I would like to implement a backup scheme in which for the past week, I have daily full backups with complete WAL logs for point-in-time-recovery. Past a week, I would like to keep only daily ...
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PostgreSQL Logical Replication Slot Lagging with Empty Tables—Why Does Setup Order Matter?
I’m running a wal-consumer pod in a PostgreSQL environment that streams WAL logs from a replication slot. However, I noticed that the order in which I set up my services affects whether the consumer ...
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Database crash just before appending the checkpoint entry to write ahead log
From what I read about WAL, its an append-only file where all the operations to the DB are written to before the operations are actually performed to the data.
There is also a concept of a "...
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PostgreSQL Failure To Reinitialise Replica With pg_basebackup [duplicate]
I have a master-replica PostgreSQL 9.5 setup.
I'm trying to reinitialize the replica by doing the following:
Stop replica service ( /etc/init.d/postgresql stop )
Clear data directory ( rm -rf /path/...
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How to create a pg_basebackup for without streaming?
I have a primary and a replica Postgres database that are never connected to each other. We have another layer of technology to store a base backup and the WAL files to and those will get synced to ...
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How to flush WAL files?
I'm trying to force WAL files to be flushed on to the disk so that I can copy them somewhere else. I believe CHECKPOINT is the command I'm interested in but it doesn't seem to work.
I have a docker ...
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How to lock an entire Postgres database
I have a process (for backup and replication using binary logs) that works in MySQL that I want to replicate for Postgres databases (using WAL):
Lock database (FLUSH TABLES WITH READ LOCK;)
Disable ...
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Advice on postgreSQL table logging
I am thinking I can turn off logging for certain tables in my PostgreSQL analytic data warehouse. There are a core set of very large tables (between 50 and 500Gb) that are completely rebuilt at the ...
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Shared buffers, WAL buffers and Checkpointers
I am taking this EDB PostgreSQL essential course and Instructor explained about PostgreSQL architecture referring to the diagram that, whenever a client make an update request and suppose data is ...
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Why does PostgreSQL want max_wal_senders equal to 0 and greater than 0 at the same time?
We're running a backup process based on pg_basebackup of a Postgres 14.5 database that creates a lot of WAL archive files and using up huge amounts of disk space. As we don't really need the WAL ...
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When are wal released or removed in postgresql?
I am relatively new to postgresql administration and I still have doubts about the operation or management of the wal files, specifically how these files are released or deleted, have the conception ...
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General questions about write ahead logs and recovery
I've recently learned about write ahead logs and failure recovery in the context of key-value stores like Cassandra and have some follow-up questions:
Do WALs get persisted into smaller snapshots so ...
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