netscout pfs

page wait, and pageiolatch_* is the IO waiting for the data page.Io_completion This wait type represents a variety of synchronous read and write operations in the data file that are not related to the table and are read from the transaction log. The following scenarios are included:1. Read log blocks from the transaction log (during any operation that causes the log to be read from disk-for example, recovery)2. In many operations, such as recovery, DB startup, read from disk allocation bitmap (

gives you more granular control over your backup and restore strategy. You can run the DBCC CHECKDB command at the filegroup level instead of the database level. Usually, you should have at least one from a filegroup, where you can store the database objects you create yourself. You should not store other system objects created by SQL Server for you in the primary filegroup.Multiple filesWhen you create your own filegroup, you also need to put at least one file in it. Additionally, yo

page is dedicated to the allocation and management of data spaces, including: PFS pages (page free space): Record whether a page is assigned, in a mixed or consistent extension, and how much space is available on the page; Gam page (Global allocation MAP) and Sgam page (secodary Global allocation map): Used to record the location of an idle extension or a mixed extension containing free pages. Sqls Comprehensive utilization of these three types of pa

simple to call this page too many sessions, then reduce the access to the page. 1. Use the index optimization statement to minimize the number of pages read by SQL. 2. Find ways to spread the page's data across multiple pages. 3. Consider read-write separation.The pagelatch_x on tempdb mainly occurs on several pages of GAM,SGAM,PFS because order By,group by, temporary table, table variable, lazy operator. will be used to tempdb, which opens up a spac

exceeds 8 pages, the data page is allocated from the consistent extension. The space page is dedicated to the allocation and management of data spaces, including: PFS pages (page free space): Record whether a page is assigned, in a mixed or consistent extension, and how much space is available on the page; Gam page (Global allocation MAP) and Sgam page (secodary Global allocation map): Used to record the location of an idle extension or a mixed exten

Specifies that rows cannot span data pages, so the maximum amount of data recorded per row is only 8K. This is why char and varchar are two types of string type that are limited to 8K, and storing more than 8K of data should use the text type, in fact, the value of the field of the text type cannot be directly entered and saved, it simply stores a pointer , pointing to An extension of a number of 8K text data pages, where real data is placed in these data pages. The page has a space page and th

the corrupted data page is1. Allocation page: GAM, Sgam, and PFS pages2. Start page for all data filesIf the above two types of corruption occur, you cannot restore the page by this backup. If this is the case, it is recommended that you consider finding a suitable time period for a full-library recovery operation. (recommended)D, the above situation is in the case of a backup, if there is no database backup, then we can only choose the last move, th

are three main types of latch waiting. Buffer (BUF) Latch. Used to protect an index or data page. Also includes PFS, GAM, Sgam, and IAM data pages. Wait type is pagelatch_* mode Non-buffer (NON-BUF) Latch, in addition to the above data structure, other memory structures. Wait type is latch_* mode IO Latch, protection of data from disk to page read and write process, wait type is pageiolatch_* mode We can query the following st

page is allocated from the consistent extension.The space page is dedicated to the allocation and management of data spaces, including: PFS pages (page free space): Record whether a page is assigned, in a mixed or consistent extension, and how much space is available on the page; Gam page (Global allocation MAP) and Sgam page (secodary Global allocation map): Used to record the location of an idle extension or a mixed extension containing free pages.

this thing, it is the role of SQL Server every time the file is created or the space growth occurs when the old data is not clear, thereby improving performance. This can affect the CREATE database, ALTER database, restore, and autogrowth scenarios.Disadvantages/Risks:Security risk is the drawback of initiating file initialization in a timely manner.Limitations:1) log file does not apply. As for why the log file does not apply, in fact, it is not difficult to understand. Data file space allocat

pages, the data page is allocated from the consistent extension. The space page is dedicated to the allocation and management of data spaces, including: PFS pages (page free space): Record whether a page is assigned, in a mixed or consistent extension, and how much space is available on the page; Gam page (Global allocation MAP) and Sgam page (secodary Global allocation map): Used to record the location of an idle extension or a mixed extension conta

Tags: automatic PFS mod align span mount gfs picture proc1. Use the fdisk-l command to view the disks that can be partitioned2. Partitioning using the parted commandParted/dev/sdb3. Create a partitioned tableMklabelDisk type Select GPT, warning Select Yes to erase disk original information4. Use the Print command to view the current partition status5. Create a partition using the Mkpart commandPartition name OptionalFile system on requestThe start end

We've talked about various pages, including data pages, GAM and SGAM pages, PFS pages, and IAM pages. Today we'll look at the variance page (differential change MAP:DCM) and differential backup (differential backups).Variance page (differential change MAP:DCM ) : SQL Server uses the diff change page to track areas that have been modified since the last full backup. The DCM page is the 6th page in the data file. The DCM page is used to track areas th

--regardless of who mapped the GAM interval in which the area resides. The zone is also tracked by the associated GAM page, so that other IAM chains are no longer allocated. All pages of a unified zone must be assigned to the same IAM chain. Then, they do not need to be the same type of page. For example, a clustered index will have both data and index pages. When a zone is assigned to an IAM chain, pages in that area are not all allocated at once (except for large data operations), which are u