Questions tagged [checksum]
The checksum tag has no usage guidance.
28
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131
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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 ...
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3
votes
1
answer
220
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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 ...
- 133
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59
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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 ...
- 61
1
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1
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385
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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 ...
- 513
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1
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54
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 ...
- 1,066
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488
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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 ...
1
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0
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824
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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 ...
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6
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213
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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 ...
- 1,066
2
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1
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317
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]) ...
- 101
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1
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32
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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 ...
- 121
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185
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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 ...
- 307
2
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1
answer
187
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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 ...
- 107
1
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0
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361
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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 ...
- 113
2
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175
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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 ...
- 15.6k
2
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2
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175
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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, ...
- 9,752
2
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1
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8k
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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?
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46
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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 ...
- 427
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1
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874
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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 ...
- 1,071
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2
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2k
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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,
...
- 143
2
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1
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481
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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 ...
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1k
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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?
- 2,338
2
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1
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185
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 ...
- 193
0
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1
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394
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 + ...
- 181
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0
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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 ...
- 111
5
votes
1
answer
951
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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 ...
8
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answer
2k
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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 ...
- 111
2
votes
2
answers
3k
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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 ...
- 121
11
votes
1
answer
757
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 ...
- 39k