How should the script be fed to Vertica's database designer when I want to create query-specific projections ?
Can I write more then one SELECT statement inside the file that will be provided as input to the DB designer?
Create a text file with the queries you want to optimize for. When prompted in the DBD process, point it to that file.
When I was working on/discussing optimxation using Vertica Database Designer it seems like the recommended upper limit for queries in the file was 100.
If you want to weigh a query more heavily, put that in multiple times.
Related
First of all: i don't need a full-text-search engine, i don't need full-text-search in my code. I have a database with ~2000 tables, and i need to find the table and column in which certain information is stored, for developing purposes. Is there any quick way (maybe an SQL Server Management Studio trick that i should know of) to do this? I think phpmyadmin provides such a feature for mysql dbs. At the moment i'm seriously thinking of dumping the database to an .sql file and use a text editor to search for the phrases i'm looking for.
Check the INFORMATION_SCHEMA. You can select on it - there is a table containing all the field names etc. and you can then do search on that one.
I don't see a way how to do it without dynamic SQL - get list of all tables and their columns from sys.tables and sys.columns (don't forget to add proper schema if you're using them), construct query that checks for the values you're trying to find and stores table and column name in temporary table, place all queries into (temp) table and finally cursor/loop over that table executing all queries.
PS. your idea of dumping everything into *.sql files should work as well, depends on the volume of data.
I have many SQL Server databases, each with a few tables containing important (from my point of view) information. I check the data (retrieving for example maximum or minimum value) within those tables using T-SQL queries.
Since I don't want to create views for each of the databases, I'm thinking about most convenient, easier and simply the best way to prepare summary which will be updating each time when opened.
The output file (or web page) will be used internally within technical team. All members can log into database using Windows authentication.
My idea was:
Excel + dynamic T-SQL --> I want to connect to database and execute T-SQL (cursor will go through all database names)
PowerShell (showing table using Out-GridView cmdlet)
PHP - first I will ask about all database names (executing select name fromsys.databases` and then execute query for each DB)
What is in your opinion best way? Do you have any better (from programmers point of view) way of getting such report/data?
You can use SSRS Reports .You have the options of exporting the report data to several formats such as pdf ,excel ,word .You can create a dataset for all your database .Since you are interested in showing aggregation and summation of values ,SSRS reports will be pretty useful in these cases .
Is there any handy tool that can make updating tables easier? Usually I got an Excel file with the original value in one column and new value in another column. Then I write a formula in Excel to create the 'update' statement. Is there any way to simplify the updating task?
I believe the approach in SQL server 2000 and 2005 would be different, so could we discuss them both? Thanks.
In addition, these updates usually request by "non-programmer" (which means they don't understand SQL, so it may not feasible to let them do query), is there any tool that can let them update the table directly without having DBAs do this task? Also, that tool needs to limit the privilege to only modify certain tables. And better has a way rollback the change.
Create a DTS package that will import a csv file, make the updates and then archives the file. The user can drop the file in a specific folder designated for the task or this can be done by an ops person. Schedule the DTS to run every hour, day, etc.
In case your users would insist that they keep using Excel, you've got several different possibilities of getting the data transferred to SQL Server. My preferred one would be to use DTS/SSIS, as mentioned by buckbova.
However, another method is by using OPENROWSET(), which makes it possible to query your Excel file as if it was a table. I wrote a small article about it here: http://blog.hoegaerden.be/2010/03/29/retrieving-data-from-excel/
Another approach that hasn't been mentioned yet (I'm not a big fan of letting regular users edit data directly in the DB), any possibility of creating a small custom application for them?
There you go, a couple more possible solutions :-)
Valentino.
I think the best approach is to expose a view on your data accessible to users who are allowed to do updates, and set up triggers on the view to perform the actual updates on the underlying data. Restrict change to only the columns they should be changing.
This technique can work on SQL Server 2000 and 2005.
I would add audit triggers on the underlying tables so you can always track changes.
You'll have complete control, and they can connect to it with Access or whatever and perform their maintenance.
You could create some accounts in SQL Server for these users and limit their access to only certain tables and columns along with onlu select / update / insert privileges. Then you could create an access database with linked tables to these.
I am trying to reconcile data from a website and a database programmatically. Right now my process is manual. I download data from the website, download data from my database, and reconcile using an Excel vlookup. Within Excel, I am only reconciling 1 date for many items.
I'd like to programmatically reconcile the data for multiple dates and multiple items. The problem is that I have to download the data from the website manually. I have heard of people doing "outer joins" and "table joins" but I do not know where to begin. Is this something that I code in VBA or notepad?
Generally I do this by bulk inserting the website data into a staging table and then write select statments to join that table to my data in the database. You may need to do clean up first to be able to match the records if they are stored differently.
Python is a scripting language. http://www.python.org
There are tools to allow you to read Excel spreadsheets. For example:
http://michaelangela.wordpress.com/2008/07/06/python-excel-file-reader/
You can also use Python to talk to your database server.
http://pymssql.sourceforge.net/
http://www.oracle.com/technology/pub/articles/devlin-python-oracle.html
http://sourceforge.net/projects/pydb2/
Probably the easiest way to automate this is to save the excel files you get to disk, and use Python to read them, comparing that data with what is in your database.
This will not be a trivial project, but it is very flexible and straight forward. Trying to do it all in SQL will be, IMHO, a recipe for frustration, especially if you are new to SQL.
Alternatively:
You could also do this by using VBA to read in your excel files and generate SQL INSERT statements that are compatible with your DB schema. Then use SQL to compare them.
If you have a lot of Stored Procedures and you change the name of a column of a table, is there a way to check which Stored Procedures won't work any longer?
Update: I've read some of the answers and it's clear to me that there's is no easy way to do this. Would it be easier to move away from Stored Procedures?
I'm a big fan of SysComments for this:
SELECT DISTINCT Object_Name(ID)
FROM SysComments
WHERE text LIKE '%Table%'
AND text LIKE '%Column%'
There's a book-style answer to this, and a real-world answer.
First, for the book answer, you can use sp_depends to see what other stored procs reference the table (not the individual column) and then examine those to see if they reference the table:
http://msdn.microsoft.com/en-us/library/ms189487.aspx
The real-world answer, though, is that it doesn't work in a lot of cases:
Dynamic SQL strings: if you're building strings dynamically, either in a stored proc or in your application code, and then executing that string, SQL Server has no way of knowing what your code is doing. You may have the column name hard-coded in your code, and that'll break.
Embedded T-SQL code: if you've got code in your application (not in SQL Server) then nothing in the SQL Server side will detect it.
Another option is to use SQL Server Profiler to capture a trace of all activity on the server, then search through the captured queries for the field name you want. It's not a good idea on a production server, because the profile incurs some overhead, but it does work - most of the time. Where it will break is if your application does a "SELECT *", and then in your application, you're expecting a specific field name to come back as part of that result set.
You're probably beginning to get the picture that there's no simple, straightforward way to do this.
While this will take the most work, the best way to ensure that everything works is to write integration tests.
Integration tests are just like unit tests, except in this case they would integrate with the database. It would take some effort, but you could easily write tests that exercise each stored procedure to ensure it executes w/o error.
In the simplest case it would just execute the sp and make sure there is no error and not be concerned about the actual results. If your tests just executed sp's w/o checking results you could write a lot of this genericly.
To do this you would need a database to execute against. While you could setup the database and deploy your stored procs manually, the best way would be to use continuous integration to automatically get the latest code (database DDL, stored procs, tests) from your source control system, build your database, and execute your tests. This would happen every time you committed changes to source control.
Yes it seems like a lot of work. It's a lot of work, but the payoff is also big. The ability to ensure that your changes don't break anything allows you to move your product forward faster with a better quality.
Take a look at NUnit and NDbUnit
I'm sure there are more elegant ways to address this, but if the database isn't too complex, here's a quick and dirty way:
Select all the sprocs and script to a query window.
Search for the old column name.
If you are only interested in finding the column usage in the stored procedure probably the best way will be do do a brute force search for the column name in the definition column sys.sql_modules table - which stores the definition for the stored procedures/functions.