Difference between revisions of "MS SQL"

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MS SQL (view source)

Revision as of 13:42, 22 September 2019

4,225 bytes added ,  13:42, 22 September 2019
m
→‎Commands and Maintenance: Added "Show database recovery modes"
(Added "Manual Backup")
m (→‎Commands and Maintenance: Added "Show database recovery modes")
 
(12 intermediate revisions by the same user not shown)
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#* Delete all historical data (backup/restore, SQL Server Agent and Maintenance plan histories)
#* Delete all historical data (backup/restore, SQL Server Agent and Maintenance plan histories)
#* Older than 2 weeks
#* Older than 2 weeks
# '''Back Up Database Task'''
#* Backup type: Full
#* Databases: All databases
#* Backup will expire: Leave unticked
#* Create a backup file for every database: Update as appropriate
# '''Reorganise Index Task'''
# '''Reorganise Index Task'''
#* All user databases
#* All user databases
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#* Update: All existing statistics
#* Update: All existing statistics
#* Scan type: Full scan
#* Scan type: Full scan
# '''Back Up Database Task'''
#* Backup type: Full
#* Databases: All databases
#* Backup will expire: Leave unticked
#* Create a backup file for every database: Update as appropriate
# '''Maintenance Cleanup Task'''
# '''Maintenance Cleanup Task'''
#* Delete files of the following type: Backup files
#* Delete files of the following type: Backup files
#* File extension: <code>bak</code>
#* File extension: <code>bak</code>
#* File age:  Select as appropriate
#* File age:  Select as appropriate
Be aware rhat the '''Reorganise Index Task''' can cause lots of activity to be generated in the transaction log, therefore if your recovery mode is ''Full'' (rather than ''Simple''), the transaction log can grow large very quickly.  If performing on a database that's been running for some time this can be an issue.  Consider setting the recovery mode to ''Simple'' for the first run, or perform at a time when if your transaction log fills you can recover without too much disruption to applications using the database.


=== Hourly Transaction Log Backup ===
=== Hourly Transaction Log Backup ===
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== Commands and Maintenance ==
== Commands and Maintenance ==
For performance issues, see http://www.sqlskills.com/blogs/paul/wait-statistics-or-please-tell-me-where-it-hurts/
Crib sheet of some very basic stuff, the syntax isn't exactly the same, but see also [[MySQL]]
Crib sheet of some very basic stuff, the syntax isn't exactly the same, but see also [[MySQL]]


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SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME LIKE '%'       /* Show tables */
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME LIKE '%'       /* Show tables */
SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE' /* Show base tables only (not views etc) */
SELECT table_name FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE' /* Show base tables only (not views etc) */
EXECUTE sp_who2;                                                              /* Show current processes */
SELECT name,log_reuse_wait_desc FROM sys.databases;                            /* Show why transaction log can't grow */
SELECT name,recovery_model_desc FROM sys.databases ORDER BY name              /* Show database recovery modes */
</source>
</source>


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=== Database Sizes ===
=== Database Sizes ===
Use the following in order to find the sizes of databases on your server.
<source lang="sql">
<source lang="sql">
SELECT
SELECT
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Source: http://stackoverflow.com/questions/5945360/sql-server-2008-how-to-query-all-databases-sizes
Source: http://stackoverflow.com/questions/5945360/sql-server-2008-how-to-query-all-databases-sizes
=== Table Sizes ===
Replace '''DatabaseName''' in the query below
<source lang="sql">
USE <DataBaseName>
SELECT
    t.NAME AS TableName,
    i.name as indexName,
    sum(p.rows) as RowCounts,
    sum(a.total_pages) as TotalPages,
    sum(a.used_pages) as UsedPages,
    sum(a.data_pages) as DataPages,
    (sum(a.total_pages) * 8) / 1024 as TotalSpaceMB,
    (sum(a.used_pages) * 8) / 1024 as UsedSpaceMB,
    (sum(a.data_pages) * 8) / 1024 as DataSpaceMB
FROM
    sys.tables t
INNER JOIN     
    sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN
    sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN
    sys.allocation_units a ON p.partition_id = a.container_id
WHERE
    t.NAME NOT LIKE 'dt%' AND
    i.OBJECT_ID > 255 AND 
    i.index_id <= 1
GROUP BY
    t.NAME, i.object_id, i.index_id, i.name
ORDER BY
    object_name(i.object_id)
</source>
Source: https://stackoverflow.com/questions/2094436/how-to-find-largest-objects-in-a-sql-server-database
=== Memory Usage ===
<source lang="sql">
DECLARE @total_buffer INT;
SELECT @total_buffer = cntr_value
  FROM sys.dm_os_performance_counters
  WHERE RTRIM([object_name]) LIKE '%Buffer Manager'
  AND counter_name = 'Total Pages';
;WITH src AS
(
  SELECT
      database_id, db_buffer_pages = COUNT_BIG(*)
      FROM sys.dm_os_buffer_descriptors
      --WHERE database_id BETWEEN 5 AND 32766
      GROUP BY database_id
)
SELECT
  [db_name] = CASE [database_id] WHEN 32767
      THEN 'Resource DB'
      ELSE DB_NAME([database_id]) END,
  db_buffer_pages,
  db_buffer_MB = db_buffer_pages / 128,
  db_buffer_percent = CONVERT(DECIMAL(6,3),
      db_buffer_pages * 100.0 / @total_buffer)
FROM src
ORDER BY db_buffer_MB DESC;
</source>


=== Fragmentation ===
=== Fragmentation ===
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ALTER INDEX IndexName ON TableName REORGANIZE;                      /* Online */
ALTER INDEX IndexName ON TableName REORGANIZE;                      /* Online */
ALTER INDEX IndexName ON TableName REBUILD;                          /* Offline */
ALTER INDEX IndexName ON TableName REBUILD;                          /* Offline */
ALTER INDEX IndexName ON TableName REBUILD WITH (ONLINE = ON);      /* Online - 2008 Ent and above only */
</source>
</source>


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...or the REBUILD statements...
...or the REBUILD statements...
<source lang="sql">
<source lang="sql">
SELECT 'ALTER INDEX ' + ind.name + ' ON ' + OBJECT_NAME(ind.OBJECT_ID) + ' REBUILD;'  
SELECT 'ALTER INDEX ' + ind.name + ' ON ' + OBJECT_NAME(ind.OBJECT_ID) + ' REBUILD WITH (ONLINE = ON);'  
FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) indexstats  
FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) indexstats  
INNER JOIN sys.indexes ind ON ind.object_id = indexstats.object_id AND ind.index_id = indexstats.index_id  
INNER JOIN sys.indexes ind ON ind.object_id = indexstats.object_id AND ind.index_id = indexstats.index_id  
WHERE indexstats.avg_fragmentation_in_percent > 50;
WHERE indexstats.avg_fragmentation_in_percent > 50;
</source>
==== Rebuild All Indexes ====
Unless you are running SQL Enterprise, this needs to be run when your database is '''single-user mode'''.
<source lang="sql">
USE DatabaseName                            /* Change to database name! */
DECLARE @TableName varchar(255)
DECLARE TableCursor CURSOR FOR
SELECT table_name FROM information_schema.tables
WHERE table_type = 'base table'
OPEN TableCursor
 
FETCH NEXT FROM TableCursor INTO @TableName
WHILE @@FETCH_STATUS = 0
BEGIN
DBCC DBREINDEX(@TableName,' ',0)
FETCH NEXT FROM TableCursor INTO @TableName
END
CLOSE TableCursor
DEALLOCATE TableCursor
</source>
To put into Single-User Mode
# Take database offline
#* If database won't stop, look for processes still accessing the database and kill them
# Put into single-user mode
# Put database online
#* You can only run commands from one console window/connection
<source lang="sql">
/* Find processes and kill them*/
exec sp_who2
kill 32
/* Force offline - change database name */
USE master
ALTER DATABASE DatabaseName SET OFFLINE WITH ROLLBACK IMMEDIATE
/* Force into single-user */
USE master
ALTER DATABASE DatabaseName SET SINGLE_USER WITH ROLLBACK IMMEDIATE
/* Put back into multi-user */
USE master
ALTER DATABASE DatabaseName SET MULTI_USER
</source>
</source>


[[Category:Applications]]
[[Category:Applications]]
[[Category:Microsoft]]
[[Category:Microsoft]]
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