Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [page-splits]

The process of splitting a physical storage page in two or more pages to accommodate new or changed rows.

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B-tree node split strategy in SQL Server for monotonically increasing value

Consider a B-tree index on a value that will always increase monotonically, e.g. a column of type IDENTITY. With a conventional B-tree implementation, whenever a node is full, it will be split 50%/50% and we end up with a B-tree in which (almost)…
someName
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MS SQL Page split confusion

I am a bit confused about page splits in MS SQL and I'm looking for a definitive answer. There seem to be two versions of the story: 1 - Fillfactor only affects how full pages are at the time the index is created/rebuilt. Page splits are always…
Mashchax
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Updating rows in Azure SQL Server causing unexpected page splits

I'm getting a lot of page splits in a live environment using Azure SQL Server PAAS that I don't understand. The update that's occurring should not increase the size of the row and therefore never cause a page split. Additionally, the behaviour…
Andrew Marshall
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Index Pages (page type 2)

I trying to understand page splits in SQL Server, reading WHAT IS A PAGE SPLIT? WHAT HAPPENS? WHY DOES IT HAPPEN? WHY WORRY? by Tony Rogerson CREATE TABLE mytest ( something_to_see_in_data CHAR(5) NOT NULL CONSTRAINT pk_mytest PRIMARY KEY…
Pரதீப்
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Can lowering fill factor result in more page splits?

We've been having a problem with page splits on a table that is a particular nuisance - its an audit log of activities in the database and has grown over 1TB. The main indexes are on the record type, which is an NVARCHAR(100) - because you need…
crucible
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Finding reason for page splits

So normally we have 20-85 Page splits/s but sometimes this spikes up the 700 - 2500 range. So to figure out what was happening i created a Extended Event with the following: CREATE EVENT SESSION MonitorPageSplits ON SERVER ADD EVENT…
Peter
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Why only 8kb per page?

I just want to know how they came to 8kb when striking a balance between: smaller page = more page splits bigger page = longer to look through to find value I expect there are many more pros and cons to having a bigger page but if we could start…
James Anderson
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Page Break is splitting in the middle of a single row in SSRS

I have an SSRS report for an Invoice and it generally works perfectly but occasionally it will page break in the middle of a row in the main Tablix. The row will split and leave part of the text on one page and the rest on the next. The Tablix has…
Matt
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Page Split Timing

So, imagine I have a page that I intend to cause to split. USE master ; GO IF DATABASEPROPERTYEX (N'Pages', N'Version') > 0 BEGIN ALTER DATABASE Pages SET SINGLE_USER WITH ROLLBACK IMMEDIATE; DROP DATABASE Pages ; END GO CREATE DATABASE…
ooutwire
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MSSQL Page Split Spike on AlwaysOn Readable Secondary

Recently I caught a massive page-split spike on an AlwaysOn Secondary instance that was not mimicked in any way by the active primary. I'm interested in what might cause this on a readable secondary since everything is "read-only".
vesuvious
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Is it possible to get a "pages touched" statistic from PostgreSQL?

With PostgreSQL one can measure disk reads and cache hits. Is it possible to have a clearer statistic of how many index pages were "touched" to run a query? If so, how?
audlift-bit
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Merits of inserting to temp table and renaming versus just adding/removing columns

If I add or drop columns from a SQL Server table I presume I get page splits or gaps. Since the size of the row has changed. When I use RedGate SQL Compare to create conversion scripts its strategy is to create a temporary table, copy all the data…
Matthew
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How to find if my innodb row uses overflow/off pages?

I use INNODB engine. My row format is Dynamic. For variable-length columns like TEXT, BLOB and varchar etc. , data is stored in off page and not in the same page itself. Do I have a way to determine if my INNODB row uses additional overflow…
kanaga sangeetha
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How are page splits determined internally in MySQL?

Going through this answer for a stack-overflow question, I found a fact that In The physical structure of InnoDB index pages I describe the Last Insert Position, Page Direction, and Number of Inserts in Page Direction fields of each index page.…
Dinesh Kumar
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Page splits on an empty table

I have a monitoring tool that alerted me to high page splits, 50% of new allocations. I found the following query to look and see: SELECT IOS.index_id, O.NAME AS OBJECT_NAME, I.NAME AS…
jbkelly
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