How to delete data in DMVs( system tables) in Microsoft Parallel Datawarehouse - sql-server

I need to delete some of the data in a system table. Is there anything that I can do?

You cannot delete data from DMVs, nor alter results from DMFs since they are collecting the data from sql server resource table which is unavailable to the user.
The only way to reset the data is to restart/shutdown sql server service

Related

SQL Server table daily sync of records from table A to table B

I want to create a daily process where I reload all rows from table A into table B. Over time table A rows will change due to changes in source system and also because of aging/deletion of records in the origin table. Table A gets truncated/reloaded daily in step 1. Table B is the master table that just gets new/updated rows.
From a historical point of view, I want to keep track of ALL the rows in table B and be able to do a point in time comparison for analytics purposes.
So I need to do two things, Daily insert rows from table A to table B if they don't exist and then also create a new record in Table B if the record already exists but ANY of the columns have changed. At one point I attempted to use temporal tables but I had too many false/positives on 'real' changes, basically certain columns were throwing off things because a date/time column was updated(only real change in row).
I'm using a Azure SQL Server Managed Instance database (Microsoft SQL Azure (RTM) - 12.0.2000.8).
At my disposal I have SSMS, SQL Server and also Azure Data Factory.
Any suggestions on the best way to do this or tools to help with this?
There are 2 concepts out of which you can implement any one.
Temporal table
Capture Data Change (CDC)
As CDC is the commonly used approach in which you can create an Azure data factory with a pipeline that loads delta data based on change data capture (CDC) information in the source Azure SQL Managed Instance database to an Azure blob storage.
To implement the CDC, you can you can follow this simple Microsoft tutorial Incrementally load data from Azure SQL Managed Instance to Azure Storage using change data capture (CDC)
Note: You also need to Create a storage account which is required but not given in above tutorial.

Automatically update SQL Server database from tables in MS Access

I'm new to SQL Server and trying to automatically update tables in SQL Server from tables in MS Access.
I have an Access database of metadata that must be kept updated for sending records to other groups. I also have a database in SQL Server which also has these same metadata tables. Currently these tables in the SQL Server database get updated manually by exporting the Access tables as Excel files, and then importing them into the SQL Server tables.
It's not the most efficient process and could lead to errors in the SQL Server database if someone forgets to check that they are using the most recent data from Access. So I would like to integrate some of the tables from Access to my database in SQL Server. Ideally I would like for the tables in my SQL Server database to be updated whenever Access is updated or at least update the tables automatically in the SQL Server database when I open it.
Would replicating the Access tables be the best? I am using SQL Server 2014 Developer so I think I have this capability. From my understanding, mirroring is for an entire database not just pieces of it. However, I do not want to be able to alter the metadata from SQL Server and have it reflected in Access. I cannot tell if reflecting the tables would do this...?
I also looked at this post about writing multiple insert statements but was confused (What is the best way to auto-generate INSERT statements for a SQL Server table?). Someone else suggested importing all the data into SQL Server and then using an ODBC driver to connect the two, but I'm also not sure how this would update the database in SQL Server anytime Access is updated.
If you have any suggestion and a link to easy to follow tutorial I would really appreciate it!
Thanks
In Access, go to 'External Data', ODBC Database, and connect to the SQL Server database directly - make sure you select 'Link to the data source by creating a linked table' on the first page of the wizard. Now, this linked table is available in Access, but is actually the SQL Server table.
Get rid of the local Access tables, using the new linked tables in their place in whatever queries, forms, reports, etc that you have in Access.
Now, any changes to the tables you see in this Access db ARE changes to the SQL Server database.

SQL Server best approch to append table data into Oracle database table

I have a table for bio-metric devices which capture the data as soon as the employees punch their fingers and uses SQL Server 2014 Standard Edition.
However, our legacy devices were exporting log files and we used a vb engine to push to our Oracle table and used to generate the attendance details.
I managed to export the data from SQL Server and built the first set of records. I would like to schedule a JOB with SQL Server with a condition that the Oracle table should receive ONLY the rows those are NOT already inserted from the SQL Server table.
I checked the append possibilities, which dumps the entire SQL Server table data when the job is executed thus duplicating the rows within the Oracle target table, forcing me to discard the job and to build a new one that deletes the Oracle table and recreates when the job is executed. I feel this is a kind of overkill...
Any known methods available to append only the rows those are NOT existing in the Oracle target table? Unfortunately the SQL Server tables doesn't have any unique id column for the transaction.
Please suggest
Thanks in advance
I think the best way is to use sal server replication with Oracle database as subscriber.
You can read about this solution on MSDN site:
Oracle Subscribers
Regards
Giova
Since you're talking about attendance data for something like an electronic time card, you could just send the data where the punch time is > the last time stamp synced. You would need to maintain that value some where, and it doesn't take into account retro actively entered records. If there's a record creation date in addition to the punch time you could use the created date. Further if there is a modified date in the record you could look into using the merge statement as Alex Pool suggested so you could get both new records and modifications synced to oracle.

Compare millions of records from Oracle to SQL server

I have an Oracle database and a SQL Server database. There is one table say Inventory which contains millions of rows in both database tables and it keeps growing.
I want to compare the Oracle table data with the SQL Server data to find out which records are missing in the SQL Server table on daily basis.
Which is best approach for this?
Create SSIS package.
Create Windows service.
I want to consume less resource to achieve this functionality which takes less time and less resource.
Eg : 18 millions records in oracle and 16/17 millions in SQL Server
This situation of two different database arise because two different application online and offline
EDIT : How about connecting SQL server from oracle through Oracle Gateway to SQL server to
1) Direct query to SQL server from Oracle to update missing record in SQL server for 1st time.
2) Create a trigger on Oracle which gets executed when record is deleted from Oracle and it insert deleted record in new oracle table.
3) Create SSIS package to map newly created oracle table with SQL server to update SQL server record.This way only few records have to process daily through SSIS.
What do you think of this approach ?
I would create an SSIS package and load the data from the Oracle table use a Data Flow / OLE DB Data Source. If you have SQL Enterprise, the Attunity Connectors are a bit faster.
Then I would load key from the SQL Server table into a Lookup transformation, where I would match the 2 sources on the key, and direct unmatched rows into a separate output.
Finally I would direct the unmatched rows output to a OLE DB Command, to update the SQL Server table.
This SSIS package will require a lot of memory, but as the matching is done in memory with minimal IO, it will probably outperform other solutions for speed. It will need enough free memory to cache all the keys from the SQL Server Table.
SSIS also has the advantage that it has lots of other transformation functions available if you need them later.
What you basically want to do is replication from Oracle to SQL Server.
You could do this in SSIS, A windows Service or indeed a multitude of platforms.
The real trick is using the correct design pattern.
There are two general design patterns
Snapshot Replication
You take all records from both systems and compare them somewhere (so far we have suggestions to compare in SSIS or compare on Oracle but not yet a suggestion to compare on SQL Server, although this is valid)
You are comparing 18 million records here so this is a lot of work
Differential replication
You record the changes in the publisher (i.e. Oracle) since the last replication then you apply those changes to the subscriber (i.e. SQL Server)
You can do this manually by implementing triggers and log tables on the Oracle side, then use a regular ETL process (SSIS, command line tools, text files, whatever), probably scheduled in SQL Agent to apply these to the SQL Server.
Or you could do this by using the out of the box replication capability to set up Oracle as a publisher and SQL as a subscriber: https://msdn.microsoft.com/en-us/library/ms151149(v=sql.105).aspx
You're going to have to try a few of these and see what works for you.
Given this objective:
I want to consume less resource to achieve this functionality which takes less time and less resource
transactional replication is far more efficient but complicated. For maintenance purposes, which platforms (.Net, SSIS, Python etc.) are you most comfortable with?
Other alternatives:
If you can use Oracle gateway for SQL Server then you do not need to transfer data and can make the query directly.
If you can't use Oracle gateway, you can use Pentaho data integration or another ETL tool to compare tables and get results. Is easy to use.
I think the best approach is using oracle gateway.Just follow the steps. I have similar type of experience.
Install and Configure Oracle Database Gateway for SQL Server.
https://docs.oracle.com/cd/B28359_01/gateways.111/b31042/installsql.htm
Now you can create a dblink from oracle to sql server.
Create a procedure which compare the missing records in oracle database and insert into sql server database.
For example, you can use this statement inside your procedure.
INSERT INTO "dbo"."sql_server_table"#dblink_name("column1","column2"...."column5")
VALUES
(
select column1,column2....column5 from oracle_table
minus
select "column1","column2"...."column5" from "dbo"."sql_server_table"#dblink_name
)
Create a scheduler which execute the procedure daily.
When both databases are online, missing records will be inserted to sql server. Otherwise the scheduler fail or you can execute the procedure manually.
It takes minimum resource.
I will suggest having a homemade ETL solution.
Schedule an oracle job to export source table data (on a daily
manner based on the application logic ) to plain CSV format.
Schedule a SQL-Server job (with acceptable delay from first oracle job) to read this CSV file and import it
to a medium table inside sql-servter using BULK INSERT.
Last part of the SQL-Server job will be reading medium table data
and do the logic(insert, update target table). I suggest having another table to store reports of this daily job result.

Keep Sql server table updated from Access table

I am attempting to keep a table in Sql server updated from an access table. Any time a change is made in the access table I would like that change reflected in the sql server table. The two tables can be identical. I have created an ODBC connection from access to sql server and can export the table to sql server; I just don’t know what must be done to keep that table updated. Any suggestions are appreciated.
Should this be implemented from within Access or within sql server?
Can you just add the SQL Server table to the Access database as a linked table? (Useful article on how to add linked tables)? That way users (let's hope there's not many!) of the Access database are in effect editing the SQL Server table directly.
If this isn't desirable then how about creating another table in the SQL Server database, and adding this to the Access database as a linked table. Then, add a trigger so that when an insert/update/delete is made to this table the same operation is done on your main table.
I think setting up a Linked Server in SQL Server could be easier to implement than an automatic export of data from Access.
According to the MSDN page,
Many types OLE DB data sources can be configured as linked servers, including Microsoft Access and Excel.
Server-on-SQL-2005-Server/
Access has no "event" that occurs when a row is updated/inserted/deleted that I know of. as JeffO points out data macros that could do what you want.
You could also periodically synch them. There are several techniques to periodically do the synch task (SQL Server Agent, Windows Service, Windows Scheduler, a timer in an application etc.), but still have to deal with all the problems that exist with synchronization if both tables can be modified, the worst being data conflict resolution. There is no easy solution for that.
Perhaps if you explained the problem you have that you are solving with synching data in SQL server and Access someone might be able to point you in the direction of a solution that doesn't have these problems.

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