Sql server page file size

Generally the recommendation is to have a Page File of 2. This makes sense only when you have other applications running in parallel to the SQL Server. Jeff Moden. I'm not sure if I'm reading that right so forgive me if I'm taking it the wrong way The general recommendation is to never set SQL Server to use "maximum" memory However, we need to leave GB of memory to the Windows.

That would be enough for the Windows server as long as it doesn't run any applications other than the SQL Server. Ignacio A. Salom Rangel. I agree with Jeff. I always though that setting max memory was bad practice! Could you please provide a link to a Microsoft article that supports what you said. It isn't talking about disabling the page file - it is referring to disabling the auto-size settings.

There are a great many, often contradictory , rules-of-thumb for the size and location of page files under various scenarios so the question will probably get closed as "opinion based" soon. Having said that I would highly question why that much of a page file would be used on a properly configured SQL Server.

The paging file s are used by Windows to a certain extent even when there is no paging going on. There will always be a super small usage of it, so don't turn it off. The only major times the paging file is needed is either when we have to swap page memory which would mean your server is under memory pressure or when there is a bugcheck commonly known as blue screen of death. If a bugcheck occurs and the server is set to kernel dumps, this will be fairly small - about 2 GB of the page file will be needed.

If, however, it's set to do a full memory dump then the size of the paging file will need to be the size of memory. Additionally the space required for these may change between versions of windows. I'd start at the 8 GB and go from there. Does it take some admin overhead to check every quarter, etc.? Yes, but you'll end up saving yourself a ton of wasted disk space. You could go system managed size, but again, this changes between versions of Windows and crash dump settings Sign up to join this community.

Any paging decreases performance of the server in general and indicates a memory issue. No, you do not need a page file 2. This is only needed for a full dump of memory for diagnostics to MS. Actually the recommendation never was 2. You can really follow some of the advise in the following knowledgebase " RAM, virtual memory, pagefile, and memory management in Windows " please be aware that much of it is 32 bit Windows focused and measure some of the counters mentioned.

A new table or index generally allocates pages from mixed extents. When the table or index grows to the point that it has eight pages, it then switches to use uniform extents for subsequent allocations. If you create an index on an existing table that has enough rows to generate eight pages in the index, all allocations to the index are in uniform extents.

Starting with SQL Server Allocations for master, msdb, and model databases still retain the previous behavior. The sys. Compatibility is not guaranteed. The SQL Server data structures that manage extent allocations and track free space have a relatively simple structure. This has the following benefits:. The free space information is densely packed, so relatively few pages contain this information.

This increases speed by reducing the amount of disk reads that are required to retrieve allocation information.

This also increases the chance that the allocation pages will remain in memory and not require more reads. Most of the allocation information is not chained together.

This simplifies the maintenance of the allocation information. Each page allocation or deallocation can be performed quickly. This decreases the contention between concurrent tasks having to allocate or deallocate pages. The GAM has 1-bit for each extent in the interval it covers. If the bit is 1, the extent is free; if the bit is 0, the extent is allocated. The SGAM has 1-bit for each extent in the interval it covers.

If the bit is 1, the extent is being used as a mixed extent and has a free page. If the bit is 0, the extent is not used as a mixed extent, or it is a mixed extent and all its pages are being used.

Page Free Space PFS pages record the allocation status of each page, whether an individual page has been allocated, and the amount of free space on each page. The PFS has 1-byte for each page, recording whether the page is allocated, and if so, whether it is empty, 1 to 50 percent full, 51 to 80 percent full, 81 to 95 percent full, or 96 to percent full.

It is used when the SQL Server Database Engine has to find a page with free space available to hold a newly inserted row. Indexes do not require that the page free space be tracked, because the point at which to insert a new row is set by the index key values. There is a new GAM page 64, extents after the first GAM page and it keeps track of the 64,extents following it; the sequence continues at 64,extent intervals.