Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

How to aggregate database sizes into one total

Posted on 2016-07-14
6
Medium Priority
?
63 Views
Last Modified: 2016-07-14
How would you aggregate (total) all returned rows into one number. I have so far the embedded code. Thanks

DECLARE @SQL VARCHAR(MAX)
SELECT @SQL = COALESCE(@SQL + CHAR(13) + 'UNION ALL
' ,'') + 'SELECT ' +
'sum(size * 8 /1024.0)/1000 AS GB from ' + QUOTENAME(name) + '.dbo.sysfiles'
FROM sys.databases
ORDER BY name
 
EXECUTE (@SQL)

Open in new window

0
Comment
Question by:barnesco
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 66

Expert Comment

by:Jim Horn
ID: 41710893
Not really following your code, but if you have a query with UNION ALL and want an aggregate value, one way is to throw the whole thing into a subquery and then sum.  For example

SELECT SUM(a.companies) as the_total
FROM (
  SELECT COUNT(name) as companies FROM whorehouses
  UNION ALL
  SELECT COUNT(name) FROM burgerjoints) a

Open in new window

0
 

Author Comment

by:barnesco
ID: 41710913
I'm trying to find the sum of all database sizes distilled into one number. I did accidentally include some extra code, so this will clean it up:

DECLARE @SQL VARCHAR(MAX)
SELECT @SQL = COALESCE(@SQL + CHAR(13) + 'UNION ALL
' ,'') + 'SELECT ' + 'sum(size * 8 /1024.0)/1000 AS GB from .dbo.sysfiles'
FROM sys.databases
 
EXECUTE (@SQL)

Open in new window

0
 
LVL 70

Expert Comment

by:Scott Pletcher
ID: 41710966
Here's some points to consider along with the code below:

1) I've separated data size and log size, as log size can vary considerably over time (esp. if you shrink log files a lot: definitely not recommended, but many people still do it).

2) dbo.sysfiles is such an ancient view that I switched to using sys.database_files instead

3) You might want to consider tempdb separately, although for now I left it in the totals.


SELECT data_size_gb, log_size_gb, data_size_gb + log_size_gb AS total_gb
FROM (
    SELECT
        CAST(SUM(CASE WHEN df.type_desc = 'LOG' THEN 0 ELSE df.size END) / 128.0 / 1000.0 AS decimal(9, 3)) AS data_size_gb,
        CAST(SUM(CASE WHEN df.type_desc = 'LOG' THEN df.size ELSE 0 END) / 128.0 / 1000.0 AS decimal(9, 3)) AS log_size_gb
    FROM sys.database_files df
) AS derived
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
LVL 30

Accepted Solution

by:
Olaf Doschke earned 2000 total points
ID: 41711003
What did you do? It is essential to prefix .dbo.sysfiles with each database name and you removed that part of the code. Your first code was correct, you just need to sum all the values  after unioning.

DECLARE @SQL VARCHAR(MAX)
SELECT @SQL = COALESCE(@SQL + CHAR(13) + 'UNION ALL
' ,'') + 'SELECT ' +
'sum(size * 8 /1024.0)/1000 AS GB from ' + QUOTENAME(name) + '.dbo.sysfiles'
FROM sys.databases

EXECUTE ('Select Sum(DBSizes.GB) as InstanceGB FROM ('+@SQL+') as DBSizes')

Open in new window


Bye, Olaf.
0
 
LVL 70

Expert Comment

by:Scott Pletcher
ID: 41711053
CORRECTION:
I needed to use "sys.master_files" rather than "sys.database_files".
There is sometimes a slight lag before the sys.master_files view reflects db size changes, but it shouldn't really be significant, and a query against master_files will run much faster.


SELECT data_size_gb, log_size_gb, data_size_gb + log_size_gb AS total_gb
FROM (
    SELECT
        CAST(SUM(CASE WHEN mf.type_desc = 'LOG' THEN 0 ELSE mf.size END) / 128.0 / 1000.0 AS decimal(9, 3)) AS data_size_gb,
        CAST(SUM(CASE WHEN mf.type_desc = 'LOG' THEN mf.size ELSE 0 END) / 128.0 / 1000.0 AS decimal(9, 3)) AS log_size_gb
    FROM sys.master_files mf
) AS derived
1
 

Author Closing Comment

by:barnesco
ID: 41711113
Thanks, that worked
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

When trying to connect from SSMS v17.x to a SQL Server Integration Services 2016 instance or previous version, you get the error “Connecting to the Integration Services service on the computer failed with the following error: 'The specified service …
This month, Experts Exchange sat down with resident SQL expert, Jim Horn, for an in-depth look into the makings of a successful career in SQL.
Via a live example, show how to setup several different housekeeping processes for a SQL Server.
Viewers will learn how to use the SELECT statement in SQL to return specific rows and columns, with various degrees of sorting and limits in place.

636 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question