I'm going to write an advanced whitepaper on interpreting the results of CHECKDB in SQL Server 2005 (mostly applicable to SQL Server 2000 as well), should be available before end of the year. Couple of questions for you:
1) would this be interesting/useful to you?
2) anything in particular you'd like to see covered?
Thanks
Paul Randal
Dev Lead, Microsoft SQL Server Storage Engine
(Legalese: This posting is provided "AS IS" with no warranties, and confers no rights.)
I used SET STATISTICS TIME ON to get execution stats for a query. I found that the CPU Time was sometimes greater than the elapsed time. How is this possible? The query does not use any parallelism since I used the query option MAXDOP 1. Is the elapsed time wait time? Is the total execution time the sum of the CPU time and elapsed time?
Is there a whitepaper or other documentation that talks about SQL2000performance limits?For example, transaction/sec limit? (Which I understand that hardware configwould be a factor)thanks
I have a job whose first step is to run a DTS package via a DTSRUN Operating System Command. I get the following message.
DTSRun: Loading... DTSRun: Executing... Error: -2147220499 (800403ED); Provider Error: 0 (0) Error string: No Steps have been defined for the transformation Package. Error source: Microsoft Data Transformation Services (DTS) Package Help file: sqldts.hlp Help context: 700. Process Exit Code 1. The step failed.
Prior to 2/29/2000, it had run dozens of times successfully, the last time on 2/23/2000.
I ran the DBCC SHOW_STATISTICS command for all of my indexes; I was told that high density numbers are bad, low numbers good. I have some questions about my results, though; I'm not sure how to interpret them.
Of 48 indexes, 14 have a density of 0. Does this mean that the indexes are not selective enough? Does it mean they're garbage and I should toss them?
6 have a density of NULL. They are all primary keys. I suppose this just means that they're never used because these tables are rarely queried. Would this assumption be correct?
13 have a density of 1. I have no idea what this means.
The others have densities ranging from 0.01210491 to 0.5841165. I was told that the lower this number is, the more selective and thus more useful an index is. I think 0.5841165 is too high a number. Would this be correct?
I'm designing a new database which will be the back-end to a heavily-used web-based application (all these terms are relative - I guess the use won't be that heavy in the grand scheme of things, I'm only talking 100 users or so at the very most). Data from the old application database will be migrated to this one, and the old database is around 7GB in size after 5 years of use.
I have two different ways of linking some tables in mind, one which is slightly more complex than the other but which potentially has benefits over the simpler method. However, I'm concerned that I might be 'over-cooking' the design, and that performance would suffer as a result, so I've tried creating the two different versions of the database (the part of it I'm concerned with, anyway), one for each of the solutions I've got in mind, migrated the data into the relevant tables and carried out some queries on the data to collect some statistics.
The problem is that, whilst I can see that the more complex method is more expensive, as expected, I don't really understand if the difference is significant. Since I don't know what the numbers in the Client Statistics window actually mean (there are no units! I'm guessing times are in milliseconds?), or how much of real-world impact the difference will have, I'm finding it hard to interpret my statistics and come to a decision.
Querying the entirety of my tables to return ~20,000 records listing one column from each of the main tables I'm playing with, the simpler method had a Total Execution Time of 199, and the more complex a Total Execution Time of 272. Is that the statistic I should be most concerned with? Is that a difference I should be concerned about? Is the difference likely to be magnified when the database is much larger and in use, such that a difference of 73 milliseconds in this test scenario could end up being as much as a whole second in production, for example?
I used a decision-tree mining-model to describe and predict fraud. The table contains 1039 records with 775 distinct value of A-number (the calling party). I used 9 columns in the model. SQL Server reports that only 3 columns are significant in predicting the fraud
- BPN_is_too_short (called party-number is too short) - Duration_is_zero - Invalid_area_code
The key-column in A-number, and the predicted column is Is_Fraud with the range of values are only 0 and 1. There's no record with NULL (missing-value) in the column Is_Fraud.
Mining Legend shows in the first split [-] 625 cases of fraud [-] 150 cases of non-fraud [-] 0 cases of missing
In addition to that, Mining Legend shows [-] 79.69% of fraud [-] 19.64% of non-fraud [-] 0.67% Missing
Now when I compare those values, they don't match. (A) 625/775 is 80.645%, not 79.69% (B) 150/775 is 19.355%, not 19.64% (C) 0 cases of NULL (missing value) should imply 0% of missing, not 0.67% of missing
Furthermore in one node (with the split on duration_is_zero), there are 541 cases of fraud and 0 cases of non-fraud. This implies the node is leaf-node. However, Mining Legend shows
514 cases of fraud, 99.35%
0 cases of non-fraud, 0.33%
[F] 0 cases of missing, 0.33%
My questions (1) Why the values don't match like in cases A through C ? (2) Why the values don't match even in cases D through F when we have no subtree at all ?
I've searched explanation by reading the mathematical reasoning, entropy, Gini index; but it does not answer the discrepancies of those values and percentages in the Mining Legend.
We have a gaming application which generates transactional data in MongoDB which eventually sends the data to SQL Server and it is in JSON format. This data needs to be used for reporting tool but visualizing this data in forms of a table is proving to be difficult. One example of a column we receive is:
We run std 2008. In my ssrs log I see this for one of our most critical reports...
library!ReportServer_0-64!2244!07/07/2015-08:24:53:: Call to GetPermissionsAction(/somedirectory/somedirectory1).... which I assume is an indication of a report starting to render by first checking permissions.
Around the time my user says he still saw the revolving arrow and he stopped the report because he felt it was running too long, I see...
webserver!ReportServer_0-64!1dbc!07/07/2015-08:54:44:: i INFO: Processed report. Report='/somedirectory/somedirectory1/importantreport', Stream=''
How can it be true that he stopped it and ssrs reports that it processed the report?
About 4 minutes later I see this entry in the log...
webserver!ReportServer_0-64!15e4!07/07/2015-08:58:34:: i INFO: Processed report. Report='/somedirectory/somedirectory1/importantreport', Stream=''
Which processed report message is right? Could there be multiples cuz of subreports? I see a number of errors and exceptions around these same times but do not know how to tie either to a specific report. Is there a way?
hi, like, if i need to do delete some items with the id = 10000 then also need to update on the remaining items on the with the same idthen i will need to go through all the records to fetch the items with the same id right? so, is there something that i can use to hold those records so that i can do the delete and update just on those records and don't need to query twice? or is there a way to do that in one go ?thanks in advance!
I have four tables: Customer (CustomerId INT, CountyId INT), County (CountyId INT), Search(SearchId INT), and SearchCriteria (SearchCriteriaId INT, SearchId INT, CountyId INT, [others not related to this]).
I want to search Customer based off of the Search record, which could have multiple SearchCriteria records. However, if there aren't any SearchCriteria records with CountyId populated for a given Search, I want it to assume to get all Customer records, regardless of CountyId.
Right now, I'm doing it this way.
DECLARE @SearchId INT = 100 SELECT * FROM Customer WHERE CountyId IN ( SELECT CASE WHEN EXISTS(SELECT CountyId FROM SearchCriteria WHERE SearchId = @SearchId) THEN SearchCriteria.CountyId
[Code] .....
This works; it just seems cludgy. Is there a more elegant way to do this?
Hello. I currently have a website that has a table on one webpage. When a record is clicked, the primary key of that record is transfered in the query string to another page and fed into an sql statement. In this case its selecting a project on the first page, and displaying all the scripts for that project on another page. I also have an additional dropdownlist on the second page that i use to filter the scripts by an attribute called 'testdomain'. At present this works to an extent. When i click a project, i am navigated to the scripts page which is empty except for the dropdownlist. i then select a 'testdomain' from the dropdownlist and the page populates with scripts (formview) for the particular test domain. what i would like is for all the scripts to be displayed using the formview in the first instance when the user arrives at the second page. from there, they can then filter the scripts using the dropdownlist. My current SQL statement is as follows. SelectCommand="SELECT * FROM [TestScript] WHERE (([ProjectID] = @ProjectID) AND ([TestDomain] = @TestDomain))" So what is happening is when testdomain = a null value, it does not select any scripts. Is there a way i can achieve the behaivour of the page as i outlined above? Any help would be appreciated. Thanks, James.
Hi All, I have a stored proc which is executing successfully...but the results of that stored proc are displaying in the Messages Tab instaed of results Tab. And in the Results Tab the results shows as 0..So, Any clue friends..it is very urgent..I am trying to call this stored proc in my Report in SSRS as well but the stored proc is not displaying there also...Please help me ASAP..
Hi all, I have the following SQLDataSource statement which connects to my Gridview:<asp:SqlDataSource ID="SqlDataSourceStandings" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" SelectCommand="SELECT P.firstName, P.lastName, T.teamName, IsNull(P.gamesPlayed, 0) as gamesPlayed, IsNull(P.plateAppearances,0) as plateAppearances, IsNull( (P.plateAppearances - (P.sacrifices + P.walks)) ,0) as atbats, IsNull(P.hits,0) as hits, P.hits/(CONVERT(Decimal(5,2), IsNull(NullIF(P.atbats, 0), 1))) AS [average], (P.hits + P.walks)/(CONVERT(Decimal(5,2), IsNull(NullIF( (P.atbats + P.sacrifices + P.walks) , 0), 1))) AS [OBP], (P.hits - (P.doubles + P.triples + P.homeRuns) + (2 * P.doubles) + (3 * P.triples) + (4 * P.homeRuns)) / (CONVERT(Decimal(5,2), IsNull(NullIF(P.atbats, 0), 1))) AS [SLG], P.singles, P.doubles, P.triples, P.homeRuns, P.walks, P.sacrifices, P.runs, P.rbis FROM Players P INNER JOIN Teams T ON P.team = T.teamID ORDER BY P.firstName, P.lastName"></asp:SqlDataSource>There are 8 teams in the database, and somehow the average and obp results are as expected for all teams except where T.teamID = 1. This doesn't make sense to me at all! For example, I get the following results with this same query: First NameLast NameTeamGPPAABHAVGOBPSLG1B2B3BHRBBSACRRBI
ErikGalvezMelville82625180.7200000.7307691.24000011322101015 As you can see, all teams except for Safe Haven's have the correct AVG and OBP. Since AVG is simply H/AB, it doesn't make sense for Gabriel Helbig's results to be 1.00000. Can anyone shed ANY light on this please?Thank you in advance,Markuu ***As a side note, could anyone also let me know how I could format the output so that AVG and OBP are only 3 decimal places? (ex: 0.719 for the 1st result)***
I have a few extremely large databases in SQL Server 6.5 sp3 (soon to be 5a - but we won't talk about that!!) NT 4.0 sp4 (about 10 GIG each). I don't have a big window of down-time in order to do any maintenance. Does anyone know of a way to be able to run dbcc checkdb or other dbcc's that I can run to verify the database yet complete within a reasonable amount of time? The last time dbcc checkdb was run, it was started Friday night and still not complete Sunday night. Over a weekend, I may have up to a 24 hour maintenance window.
Any suggestions would be appreciated. Thanks! Toni
Hai , When I ran DBCC CHECK DB of userdatabase, its reporting along with usual messages as Descriptor for system table '8' in database '8' not found in the descriptor hash table. I could'nt understand being familiar error encounterd . Any one will appreciate for the help
I recently took over a SQL server with 300 MB of data. I am relatively new to SQL 6.5 and have been reading that DBCC checkdb and checkalloc should be run at least once per week. Apparently the person before me never ran any of those checks. Is not running the database consistency checks for so long going to present a problem? has anyone run into problems when running those checks? Any advise is greatly appreciated.
I ran "dbcc checkdb(MCMSdb) with no_infomsgs" and I get the following: Server: Msg 8946, Level 16, State 12, Line 2 Table error: Allocation page (1:274992) has invalid PFS_PAGE page header values. Type is 0. Check type, object ID and page ID on the page.
What cane be done to correct this problem? Can this error prevent a user from connecting to the database?
I ran checkdb and found 4 error message on the db.. it seen like same object.. can anyone tell me what it is.. and how can i fix it? thanks !!!!
1. Server: Msg 8976, Level 16, State 1, Line 35 Table error: Object ID 2094630505, index ID 1. Page (1:809859) was not seen in the scan although its parent (1:77885) and previous (1:809767) refer to it. Check any previous errors. 2. Server: Msg 8978, Level 16, State 1, Line 35 Table error: Object ID 2094630505, index ID 1. Page (1:809860) is missing a reference from previous page (1:809859). Possible chain linkage problem. 3. Server: Msg 8976, Level 16, State 1, Line 35 Table error: Object ID 2094630505, index ID 1. Page (1:1453795) was not seen in the scan although its parent (1:1453347) and previous (1:1453796) refer to it. Check any previous errors. 4. Server: Msg 8978, Level 16, State 1, Line 35 Table error: Object ID 2094630505, index ID 1. Page (1:1453801) is missing a reference from previous page (1:1453795). Possible chain linkage problem.
Does anybody know if the results of DBCC CHECKDB are stored anywhere? If yes, where? Also, if you don't select "attempt to repair minor problems" option when you set up the maintenance plan, will SQL Server let you know about any errors Integrity check encounters? If yes, where the erros can be found?
in the SQL 6.5 documentation it says when running the DBCC CHECKDB, you should make the database read Only or DBO use only. Do you guys know if SQL 6.5 locks rows while this runs? In SQL 7.0/2000 it only locks the schema.
I am using windows nt40 and sql server 6.5 on a DEC ALPHA and accidentlly started a dbcc checkdb. Is it possible to stop the process with out damaging the database?
When running dbcc checkdb from my workstation(nt) I recieve some of the output and then I get "Connection Broken" this is on a 6.5 machine with the service pack 5, what could be causing my ODBC connection to drop during the proccess of running checkdb?
How can I make the dbcc checkdb fail so I can get the errors displayed in the report log? DBCC Checkdb is the step in the integrity job that I run once a month. What I am trying to do is when the dbcc checkdb fails for any reason, I want to get notified so I can correct the problem. I don't want to use repair fast or any other repair parameters that you can select when you run dbcc checkdb function because most of my dbs are 24x7.
I have a job set up that runs the dbcc checkdb and puts the results into a table. Then I run a query against this table to check the results of dbcc checkdb. If there are errors, I get a page that lets me know that there are some problems. When I ran this job on my production server, the job failed stating that there are problems with data integrity. So I copied this db to a dev server and recreated the job just like I have in prod. The job completed successfully withou any errors. Can anybody tell me what to look at to figure out why it failed on the prod server?
Madhur writes "Last week DBCC CHECKDB <database name> took 2 Hrs to complete on a database. Today again i have started but with the following command: dbcc checkdb (<database name>, REPAIR_FAST ).
It is now running for more than 2.5 Hrs now.
Does the execution time increases even when the DB is consistent?
Can we cancel the execution in the middle? What consequences it may have on the db?
I have a db that is about 50Gigs. Last night it went into a suspect mode and I have not been able to get any of my tables to display. I am running the dbcc checkdb. I have been running it for over 7 hrs. Do you have any suggestions as to what I should do or do you have any ideas as to how long this process might take?
Ricardo writes "We are consistently getting this error. We have check the hardware and nothing appears in the checkdk, can you help.
Thanks
Ricardo
dbcc checkdb (virtualrequest) DBCC results for 'tblVRAnswers'. Server: Msg 8928, Level 16, State 1, Line 1 Object ID 370256524, index ID 3: Page (1:243518) could not be processed. See other errors for details. Server: Msg 8939, Level 16, State 1, Line 1 Table error: Object ID 370256524, index ID 3, page (1:243518). Test (IS_ON (BUF_IOERR, bp->bstat) &&bp->berrcode) failed. Values are 2057 and -1. There are 9608 rows in 106 pages for object 'tblVRAnswers'.
CHECKDB found 0 allocation errors and 2 consistency errors in database 'VirtualRequest'.
dbcc checkdb (virtualrequest) DBCC results for 'tblvrquestions'. Server: Msg 8952, Level 16, State 1, Line 1 Table error: Database 'VirtualRequest', index 'tblVRRequestedItems.IX_NC_tblVRRequestedItems_CurrentStatusID' (ID 784825958) (index ID 2). Extra or invalid key for the keys: Server: Msg 8956, Level 16, State 1, Line 1 Index row (1:214293:372) with values (CurrentStatusID = 3 and RequestedItemID = 413260) points to the data row identified by (). There are 6614 rows in 103 pages for object 'tblvrquestions'.
CHECKDB found 0 allocation errors and 1 consistency errors in database 'VirtualRequest'
dbcc checkdb (virtualrequest) DBCC results for 'tblvrquestions'. Server: Msg 8952, Level 16, State 1, Line 1 Table error: Database 'VirtualRequest', index 'tblVRRequestedItems.IX_NC_tblVRRequestedItems_CurrentStatusID' (ID 784825958) (index ID 2). Extra or invalid key for the keys: Server: Msg 8956, Level 16, State 1, Line 1 Index row (1:214293:372) with values (CurrentStatusID = 3 and RequestedItemID = 413260) points to the data row identified by (). There are 6614 rows in 103 pages for object 'tblvrquestions'.
CHECKDB found 0 allocation errors and 1 consistency errors in database 'VirtualRequest'."
Ran DBCC CHECKDB on my database and it's returning the following:
There are 460 rows in 13 pages for object 'KPW'. Server: Msg 8928, Level 16, State 1, Line 1 Object ID 1977058079, index ID 0: Page (1:1868079) could not be processed. See other errors for details. Server: Msg 8944, Level 16, State 1, Line 1 Table error: Object ID 1977058079, index ID 0, page (1:1868079), row 76. Test (!(hdr->r_tagA & (VERSION_MASK | RECTAG_RESV_A | RECTAG_RESV_B))) failed. Values are 173 and 193. Server: Msg 8944, Level 16, State 1, Line 1 Table error: Object ID 1977058079, index ID 0, page (1:1868079), row 76. Test (ColumnOffsets <= (nextRec - pRec)) failed. Values are 16374 and 33. Server: Msg 8964, Level 16, State 1, Line 1 Table error: Object ID 1977058079. The text, ntext, or image node at page (1:1867931), slot 8, text ID 205274873856 is not referenced. Server: Msg 8964, Level 16, State 1, Line 1 Table error: Object ID 1977058079. The text, ntext, or image node at page (1:1867932), slot 0, text ID 205275004928 is not referenced. Server: Msg 8964, Level 16, State 1, Line 1 Table error: Object ID 1977058079. The text, ntext, or image node at page (1:1867932), slot 2, text ID 205275136000 is not referenced. Server: Msg 8964, Level 16, State 1, Line 1
