SQL 2012 :: CDC (Change Data Capture) Is Not Capturing Data Correctly
Apr 21, 2014
I am using SQL Server 2012 and to me a part of data captured by CDC is not making sense.
I have a table called 'Schema.Table1', and I enabled CDC on it by running 'sys.sp_cdc_enable_table'. I see that a table called 'cdc.Schema_Table1_CT' got created which now gets an entry when ever I Insert, Update or delete a record in the original table.
Till this point every thing works fine.
My original Table has a NOT NULL INT column called 'AuditTrackerUserID' with a default value of 1996. My application does not provides a value for this column, but because the column itself has a default value, records get inserted without error.
When I try to execute the following Query I see multiple records with __$operation of 3 and 1.
SELECT * from cdc.Schema_Table1_CT where AuditTrackerUserID IS NULL
My expectation is that I should not ever see any record returned by this query because AuditTrackerUserID is a not null column, but I do.
I have a requirement to implement CDC for 50+ tables to implement incremental data changes warehouse/reporting rather than exporting the whole table data. The largest table is having more than half a billion records.
The warehouse use a daily copy of OLTP db (daily DB refresh). How can I accomplish this. Is there a downside in implementing CDC just for the sake of taking incremental changes on the tables?
Is there any performance impact if we enable CDC on OLTP db?
Can we make use of the CDC tables on the environment we do daily db refresh so that the queries don't hit OLTP database?
What is the best way to implement CDC to take incremental changes for reporting.
Again, looking for the best way to do this with SSIS.
I have a source table and I'd like to load it to a database daily, capturing what changed.
This is not a dimentional table but a fact table.
So, what I;d need to do for each record is to see if the record already exists (using business key) and if it does - compare some of the data fields and of there are changes - register it somehow and if not changes ignore.
Right now, the only two ways I see to do it with SSIS:
- Use Slowly Chaging Dimentions transformation
- Use Lookup and customize SQL, adding something like: WHERE key = ? and (field1 <> ? or field2 <> ?...)
When using Change Data Capture on SQL Server 2012 I have researched that you cannot truncate data in a table. Is this also true if one wanted to delete data from the table? Getting a little confused about what DDL statements can be ran against a table with CDC enabled. Does CDC have to be disabled before performing certain DDL statements against a table?
I would like to safeguard the truncation and dropping of certain tables within the dbo schema. Wondering if I could do this with one fail swoop with CDC enabled on those tables. The other option would be to use a DDL trigger to prevent certain DDL statements to be performed.
We have enabled Change Data Capture for auditing our table changes in SQL Server 2008. There is a request to NULL out a few columns (for all rows) in a couple CDC tables, due to compliance with a certification. Is there a compelling reason not to modify these tables and to leave the audit trail as-is?
SQL Server 2008R2: Enabling Change Data Capture on a replicated database or its tables will have any performance impact on existing transactional replication.Is it possible to use both of them con temporarily.
Hi All, I am now working on the design phase of my project, we are looking to implement Change Data Capture (CDC) but i need some help if you guys has implemented before using the SSIS 2005 componets. I am trying to use the Following:
Source---------Derived Column---------Lookup---------------Conditional Split (to split New records and Updated Records)-----------Destination. Respectively. Lets make it clear, my source holds (Old records and newly added or Updated records), the Derived Column is to Derive new columns called Insert_Date and Update_Date. The Lookup i am Using is to look the Fact_Table(the Old Records) as Reference, and then based on this lookup i will split the records on timely based using the Conditional Split. My question is 1. Am i using the right components? 2. what consideration should i have to see to make it true (some Logics on the conditional split)? 3. Any script which helps in this strategy? 4. If you have a better idea please try to help me, i need you help badly.
Each one of the tables listed below has a “CreateDateTime” and “UpdateDateTime” fields, I need to get yesterday changes, I can get any record where either CreateDateTime or UpdateDateTime is greater than midnight yesterday butI need to watch dates on all of the tables so I need to do atleast 10 date checks.
If any table shows an updated or created record, I need to gather ALL of the information for that customer. So, if my name didn’t change (SCUS table), but my email does (SEML table), I have to pull out both the SCUS and SEML tables (and the others, of course). So It may not be simple WHERE clause, How can I achieve this:
Or can it record before and after column changes based on the LSN only?
An extract from a file based legacy accounting system is performed every night. The system does not have a primary key because transactions are managed through program code. (the more things change...). The extract is copied to text in Unix and FTP'd to Windows, where the file is loaded into SQL Server by kill & fill. Because of the expense of modifying the source system, there is enormous inertia/resistance to injecting a primary key at the source, so kill & fill it stays.
In reading about Change Data Capture, it seemed to me that column level insert update and delete are stored in tables that remember the before and after content of each column tracked. In my reading I have seen many references to the LSN to decide when and what to record as changed, but I have not seen any refereference to the necessity of a primary key for Change Data Capture to work. This is in contrast to replication, where the requirement for the existence of a primary key is made plain.
Is it possible to use Change Data Capture against a table without a primary key? How to use it to change the extract from kill and fill to incremental.
I have located a bug in the functions cdc.fn_cdc_get_net_changes_<capture_instance> generated when you enable cdc on a table. This bug can be triggered if 2 rows are created in the _CT table having the same values for the __$start_lsn, __$seqval and the table's key column(s). From research on the internet I have found such rows can be created by a "deferred update": a single update statement in which a column that is part of a unique constraint is updated.
In order to report the bug with Microsoft I need to create a complete series of steps-to-reproduce. But even though the situation happens several times a day in our production environment, I have not yet been able to reproduce it in my test environment.I need a single update statement (plus maybe some steps in advance) that make that the log reader inserts 2 rows into the _CT table, one with __$operation = 1 (delete) and another with __$operation = 2 (insert) as opposed to the single row with __$operation = 4 that it inserts for a normal update. Below is the script I have so far to create a fresh database, enable cdc, create a test table, insert some data and update this data.
I would have liked the last update statement to be handled as a "deferred update". However in all of my tests the log reader just simply inserts a single row into the cdc.dbo_NETTEST_CT table.how to reproduce the situation where I get the 2 rows with __$operation 1 and 2 from a single update statement instead of the single row with __$operation = 4.
I would like to fetch the data flow component name while package is executing. Since system variable named [System::SourceName] only fetches name of the control flow tasks? Is there a way to capture them?
I am in process to develop TSql code to identify change in data.
I read about Binary_checksum and hashbyte. Some people say hashbyte is better than binay_checksum as chances of collision are less.
But if we may consider following, chances exist in hashbyte too. My question is what is the best way to compare data to identify change (I can't configure CDC) ?
Hi, Create Table tb_mismatch (x int) Create Procedure proc_mismatch as begin insert into tb_mismatch values('s') if @@error<>0 begin print ' entered error loop' end print 'successfully exited' end exec proc_mismatch --executing the proc Now, when i try to capture the above error its not getting trapped..its directly going to the final end statement. I have even tried calling subprocedures so that it comes out of the inner procedure and by some means i can move forward in the outer proc,but even that failed. The proc. is able to capture all the other errors like primary key violation,binary data truncated etc but not the datatype mismatch error (mainly int with varchar...) any ideas are highly appreciated. Thanks & regards, Pavan.
I have a web service that does an SQL select against a database that contains international data, however when this is displayed from the web service the text such as "Rue Emile Féron 168" is not shown correctly and the 'é' is shown as a comma. Can someone advise what changes I need to make to the coding. Also our own tables have varchar fields and I'm assuming the "é" data will be saved correctly ???
Hello, I am really dripping wet behind the ears on this and would really appreciate some help. I am setting up my first SQL table and am lost at trying to choose data types for my fields. Basically, all I am doing is setting up a contact form. It is going to ask for phone number, name, address, city, state, zip, etc. I will also have two fields which if I were using an Access db, would be "memo" with say, 500 characters. So in researching SQL data types, I came across the following:
char Fixed-length non-Unicode character data with a maximum length of 8,000 characters.
varchar variable-length non-Unicode data with a maximum of 8,000 characters.
text Variable-length non-Unicode data with a maximum length of 2^31 - 1 (2,147,483,647) characters.
nchar Fixed-length Unicode data with a maximum length of 4,000 characters.
Can someone shed some light on what I need for simple fields like street, name, city, and more importantly, description? I will also have a "premium" field which should be a "yes" or "no". I am thinking a data type of bit, which is set to 1 or 0? Thanks for any help, I appreciate it so much. TOm
Ok I wrote a SSIS package that will pull down data from my AS/400 and populate a SQL Server table with the data.
1)The data is being pulled from my China configured AS/400. It is configured to handle DBCS 2)The SQL Server tables are configured to handle DBCS by using the nvarchar datatype. 3)When I run this package on my machine against the production server, it works perfectly. 4)When I run this package on my test SQL Server against the production server,it works perfectly. 5)When I run this package on my production SQL Server it brings down all the records, but does not bring down all the fields. Most of the character fields are left blank.(not all)
I do not understand why this is doing this. Can anyone shed any light on this problem? Thank you.
Ok I wrote a SSIS package that will pull down data from my AS/400 and populate a SQL Server table with the data.
1)The data is being pulled from my China configured AS/400. It is configured to handle DBCS 2)The SQL Server tables are configured to handle DBCS by using the nvarchar datatype. 3)When I run this package on my machine against the production server, it works perfectly. 4)When I run this package on my test SQL Server against the production server,it works perfectly. 5)When I run this package on my production SQL Server it brings down all the records, but does not bring down all the fields. Most of the character fields are left blank.(not all)
I do not understand why this is doing this. Can anyone shed any light on this problem? Thank you.
Ok I wrote a SSIS package that will pull down data from my AS/400 and populate a SQL Server table with the data.
1)The data is being pulled from my China configured AS/400. It is configured to handle DBCS 2)The SQL Server tables are configured to handle DBCS by using the nvarchar datatype. 3)When I run this package on my machine against the production server, it works perfectly. 4)When I run this package on my test SQL Server against the production server,it works perfectly. 5)When I run this package on my production SQL Server it brings down all the records, but does not bring down all the fields. Most of the character fields are left blank.(not all)
I do not understand why this is doing this. Can anyone shed any light on this problem? Thank you.
I have a table with a field "StartedAt". I wish to capture all the data in that table which has Yestarday's StartAt date. My script below captures the data which has yestardays "StartedAt" info as well as today's date till now. How can i capture only yestardays info only.
SELECT StartedAt FROM myTable WHERE StartedAt >= DATEADD(day, DATEDIFF(day, 0, getdate()), -1)
I have the following code but do not know the best way to return the updatedDataTable back to the database. I believe I can use the Update method of theData Adapter, BUT if true, I also believe I have to 'long-hand' write codefor each individual column data that's being added......this seems a bitdaft considering that the data is already in the disconnected data table.Have I lost the plot?? Based on the code below, what is the correctapproach?Note: sqlcnn is defined at module level.Public Sub AddRequest(ByVal Eng As String, ByVal Bran As String, ByVal ReqAs String) Implements IHelpSC.AddRequestDim dtNew As New DataTable("dtNew")Dim drNew As DataRowsqlda = New SqlDataAdapter("SELECT * FROM ActiveCalls", sqlcnn)sqlda.Fill(dtNew)'Add and populate the new datarow with'data passed into this subroutinedrNew = dtNew.NewRowdrNew("CallTime") = Format(Date.Now, "dd MMM yyyy").ToStringdrNew("Engineer") = EngdrNew("Branch") = BrandrNew("Request") = ReqdtNew.Rows.Add(drNew)End SubHope one of you wizards can help.Rgds.....and Merry Christmas.Phil
I want to make data changes in read_only database , that's why i must set database read_write. While database is at read_write mode, i want to be sure that no one makes change in database.
For this aim, i write the code below, but i suspect that after setting the database read_write, till the setting database single_user ,is it possible get DML script from another user. Is the code below enough for this operation. Or is there another way?
Reminding: Read_only database can not be set single_user mode. That's why, first you must set database read_write.
The code;
use master alter database xxx set read_write with rollback immediate alter database xxx set single_user with rollback immediate
use xxx update tablexxx set columnxxx=yyy use master alter database xxx set read_only with rollback immediate alter database xxx set multi_user with rollback immediate
I want to tune the indexes on my database and I am trying to use the SQL Server Profiler to collect data for the Index tuning wizard to analyze. My question is what do I need to trace with the profiler so that the Index tuning wizard can work? I am looking at the trace properties in Profiler at the Events, Data Columns, and Filters tabs but I have no idea of what I need to capture.
Conditions If there are about 100 records in text file, if there is an error at 43 and at 67 record respectively , it should capture 43 and 67 record in failure folder and remaining 98 records , should be processed
1) Successful record into table and move the success record from the folder to new path say( Success folder) (98 records to table) 2) Unsuccessful records to new path (Failure folder) (2 lines ) 3) Error message to capture the failed records and store them in another folder(Error log) (2 line failure information)
While writing the 3rd condition to error log table , it has to point out the record which is failed for what reason, say it may be due to invalid data type for column 10 for 43 record, and incorrect syntax error at 67 record.
I have 2 tables, table one with 772 pieces of compliant data. Table 2 has 435 pieces of data that meet another criteria (all the columns are identical it was just passes through an additional filter). I need to capture the values that are excluded from table 2.
Example Table 1 ID some value 1 x 2 x 3 x 4 x 5 x
Table 2 ID some value 2 x 3 x 5 x
I need to capture the data from ID 1 and 4 and assign a new value to it, it is extra compliant data. Thanks!
i someone had teach me how to write a query in datatable. however i need to get the data out from my database rather than the data table. can someone teach me how should i do it?esp at the first like.... like DataTable dt = GetFilledTable() since i already have set of data in my preset table i should be getting data from SqlDataSource1 right ( however i am writing this in my background code or within <script></script> so can anyone help me? protected void lnkRadius_Click(object sender, EventArgs e) { DataTable dt = GetFilledTable(); double radius = Convert.ToDouble(txtRadius.Text); decimal checkX = (decimal)dt.Rows[0]["Latitude"]; decimal checkY = (decimal)dt.Rows[0]["Longitude"]; // expect dt[0] to pass - as this is our check point // We use for rather than fopreach because the later does not allow DELETE during loop execution for(int index=0; index < dt.Rows.Count; index++) { DataRow dr = dt.Rows[index]; decimal testX = (decimal)dr["Latitude"]; decimal testY = (decimal)dr["Longitude"]; double testXzeroed = Convert.ToDouble(testX -= checkX); double testYzeroed = Convert.ToDouble(testY -= checkY); double distance = Math.Sqrt((testXzeroed * testXzeroed) + (testYzeroed * testYzeroed)); // mark for delete (not allowed in a foreach - so we use "for") if (distance > radius) dr.Delete(); } // accept deletes dt.AcceptChanges(); GridView1.DataSource = dt.DefaultView; GridView1.DataBind(); }
My objective is to extract the source table data from SQL/Oracle or CSV files and load into destination table using CDC mechansim. May I know the steps required to implement in production from development.
Let me preface by saying I am not very familiar with SSIS.
Ideally, since the Transfer SQL Server Objects task can do all tables, I would like to use it to copy only data from one server to a new server that has the tables pre-created. When I encounter any kind of error, in addition to the error information provided by SSIS, I also need the actual row data.
If using the Transfer Object task can't do that, how would I loop through all the tables on an OLEDB source and capture the same error information on the destination? I figured out how to do the Data Flow a table with a redirect error output but that does not give me the actual row data.
I have a report that has ten pages (essentially ten different reports). Each page has one, large main chart and then three smaller charts stacked on top of each other off to the right. The layout is in landscape. When I render the report in Reporting Services, the layout looks fine. If I export it to Adobe, it is also fine. However, when the report is emailed as a PDF attachment, the main chart on each page is completely missing. Has anybody experienced something simliar? I was having issues with the layout, and decreasing the height of each page fixed everything, but created this new problem. I am using Adobe 7.0. Thank you.
