Questions tagged [checksum]

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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 ...
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0answers
59 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 ...
6
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1answer
194 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 ...
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1answer
29 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]) ...
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1answer
28 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 ...
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0answers
93 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 ...
2
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1answer
44 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 ...
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0answers
203 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 ...
2
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1answer
115 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 ...
2
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2answers
105 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, ...
1
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1answer
5k 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?
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1answer
42 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 ...
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1answer
592 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 ...
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2answers
950 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, ...
2
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1answer
312 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 ...
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1answer
743 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?
2
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1answer
93 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 ...
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1answer
356 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 + ...
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0answers
711 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 ...
5
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1answer
627 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 ...
8
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1answer
2k 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 ...
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2answers
2k 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 ...
11
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1answer
666 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 ...