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Questions tagged [checksum]

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Fix invalid checksum in database that causes pg_dump to fail

I have a Postgres 9.6 database that is corrupted. The hardware it was running on went bad, and there is at least one corrupted page in the DB. When running pg_dump I get the following error: pg_dump: ...
Fabian's user avatar
  • 103
0 votes
0 answers
170 views

Checksum algorithm for multiple rows

I am looking for a fast checksum function to be used in postgres and thought about Adler-32 and crc32c. Postgres don't seem to have such functions implemented by default. The only way i found to ...
Yuki's user avatar
  • 21
1 vote
0 answers
244 views

MySQL Checksum differs but cannot find difference in table

I have two tables which are expected to be the same CHECKSUM TABLE robot, tbd_robot #Doesn't match All the column types (storage format) are the same, the engine and collation are also the same. The ...
Wistar's user avatar
  • 111
3 votes
1 answer
634 views

What are the performance implications of using checksums vs change tracking for SQL Server

Back in the day, an implementation with checksum_agg was made to check if "something changed" in a table in a SQL Server table, to then make updates in another database. The users want to ...
Ola Eldøy's user avatar
0 votes
2 answers
153 views

postgres 11.3 checksum validation post migration

I am in the process of migrating our AWS RDS postgresql from one account to another with zero downtime. I am going with pg_dump/pg_restore + AWS CDC for ongoing replication. I am looking for a way to ...
Falcon's user avatar
  • 91
1 vote
1 answer
865 views

Checksum for SQL-server tables

I'm in the process of installing applications and databases. In order to check whether a file is correct, I can simply take the checksum. Is there a way to check if a table is correct? (I realise I ...
Dominique's user avatar
  • 521
1 vote
1 answer
67 views

How to detect which indexes have checksums and which ones don't?

Is there a query that will show which tables / indexes need to be rebuilt so that they have checksums available for data verification? The DB was switched recently from torn page to checksum ...
user2368632's user avatar
  • 1,097
0 votes
1 answer
674 views

Is there a cross-platform way to compare data in one columnd on each sitde of replicated data, like a checksum or hash?

I have an Oracle 12 database with lots of tables, and I am replicating several of the tables (a subset of rows) into a SQL Server 2016 database. The subset of rows can be established with a WHERE ...
Patrick Szalapski's user avatar
1 vote
0 answers
1k views

How to repair a block based Rocksdb sst file with corrupt masked crc32 checksum in that case? [closed]

Environment I'm using the Ethereum cryptocurrency in a way which requires something called full Ethererum archival node where each new blocks (somewhat a batch of recent transactions) is added to the ...
user2284570's user avatar
6 votes
1 answer
217 views

How do pages get updated checksum when switching page verification mode from torn page to checksum?

Have an older but large db (6tb on the san) that still has its page verification option set to TORN_PAGE_DETECTION. How do you apply the new checksum to all existing pages when changing page ...
user2368632's user avatar
  • 1,097
2 votes
1 answer
448 views

What is the best way to divide data for random groups?

I would like to have persisted column which will randomly group data for 32 groups according to one of varchar key column in table. My idea was: SELECT ABS(CAST(HASHBYTES('MD5',[keyColumnFromTable]) ...
axdna's user avatar
  • 111
0 votes
1 answer
34 views

Database system checksumming to prevent network corruption not caught by TCP checksumming

Since TCP checksumming is not sufficient to detect/prevent all corruption, do modern database systems (e.g. SQL Server, MariaDB / MySQL, Oracle, etc.) use any additional checksumming of network ...
g491's user avatar
  • 121
0 votes
0 answers
245 views

Hash matches with collisions

I'm trying to improve certain matches that happen often, on many many dimension columns. So my choices as I understand are: Match on many columns Hash the columns, store the hash, match on that. If ...
Jamie Marshall's user avatar
2 votes
1 answer
328 views

Impacts of a change to the Page Verify option

There's no doubt about importance of doing regular integrity checks on production databases. I'm testing the impact of changing the maintenance plans and changing how databases are backed up. First of ...
Gio's user avatar
  • 107
1 vote
0 answers
447 views

What All Is Factored Into A MySQL Checksum? (Why Could They Be Different?)

I'm currently going through the excruciating task of moving MySQL databases from one shared web hosting environment to another. This has been a multi-month battle (and I'm learning a lot). After ...
azoundria's user avatar
  • 113
2 votes
1 answer
237 views

How to check if backups are reliable?

I generally have to restore databases to different servers after important data imports or other important and delicate database operations. I need to be sure that my backups up to that point in time ...
Marcello Miorelli's user avatar
2 votes
2 answers
244 views

Will I be notified that BACKUP encountered a CHECKSUM error if I use CONTINUE_AFTER_ERROR?

I am in the process of adding the WITH CHECKSUM flag on our daily SQL backups, as part of an effort to better ensure data integrity. I definitely want to know if a checksum error is ever encountered, ...
BradC's user avatar
  • 9,964
2 votes
1 answer
10k views

Is there any function like checksum in Oracle

I need to calculate the checksum of some columns. The built-in function checksum is used to calculate the checksum in Microsoft SQL Server. Is there any built-in function checksum in Oracle?
Noah's user avatar
  • 63
0 votes
1 answer
50 views

SQL 2016 Changing Page Verify Impact

Recently inherited a new SQL server and after some Blitz (Thanks Brent and team) checks have noticed that some of the DB's are set to Torn_Page or None for the page verify option. I want to change ...
Stockburn's user avatar
  • 419
0 votes
1 answer
971 views

Validation of data with checksum vs Binary_checksum

Based on this post, I was able to solve the performance issue by adding indexes and thought I completed my project until I ran into an issue with the checksum... I then did research (should have done ...
JohnG's user avatar
  • 1,081
1 vote
2 answers
2k views

varchar(255) field or hash field?

To consider a table with millions records and the table schema: CREATE TABLE `foos` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `foo` varchar(255) COLLATE utf8_unicode_ci NOT NULL, ...
Ben's user avatar
  • 143
2 votes
1 answer
522 views

How to verify (CHECKSUM or MD5) dataset you received over a network?

I will remotely query mysql database and I want to check that the received dataset matches the table in the host computer. How do you do that? I am fairly new to sql database. I know of Checksum and ...
ThN's user avatar
  • 123
1 vote
1 answer
1k views

what is an InnoDB Page checksum?

What is an InnoDB Page checksum exactly? Does a Page checksum only detect issues with underlying storage when writing or reading to a page/block?
Sybil's user avatar
  • 2,498
2 votes
1 answer
226 views

How to guarantee rows order

I'm trying to implement a methodology to check the integrity of a restored database. It goes as following: Create a snapshot of the database. Gather various metadata: On disk used space. Name of ...
Spack's user avatar
  • 193
0 votes
1 answer
407 views

Check integrity between servers

I have three Database servers, running PostgreSQL 9.2: master01 (Own data center USA) slave01 (Own data center USA) slave02 (AWS Australia) Both slaves use streaming replication + ...
Patrick B.'s user avatar
1 vote
0 answers
1k views

Mysql checksum for data only

I have some groups of two tables, each group table having the same structure. (dev & prod server) Their data will never change from user action, only from admin when a change occurs. I want to ...
FLX's user avatar
  • 111
5 votes
1 answer
1k views

How to Resolve Corruption Detected by BACKUP WITH CHECKSUM, But NOT DBCC CHECKDB?

Recently, I was asked to refresh a couple of databases on a test server from production. Always wanting to follow best practices, I performed the backup using the WITH CHECKSUM option, and eventually ...
Hercule Poirot's user avatar
8 votes
1 answer
3k views

Null Values in a CASE statement

I am playing around with some stuff in SSMS to learn a little more as I study for my 70-461 exam and I came across a little hangup. I am trying to create a table to play around with so I don't have to ...
user2921015's user avatar
2 votes
2 answers
3k views

Mysql checksum for master-slave replication returning different values, despite being identical

I've set up a master slave replication in mysql and to make sure that I know if the data starts getting out of sync I created a script that: Locks both databases on both servers. Prints the checksums ...
Andreas Larsson's user avatar
11 votes
1 answer
799 views

How do data checksums interact with streaming replication?

Data checksums are a new feature introduced in 9.3, and: there is a new GUC parameter "ignore_checksum_failure" which will force PostgreSQL to continue processing a transaction even if corruption ...
Jack Douglas's user avatar
  • 39.9k