DO NOT USE this for questions targeting Microsoft SQL Server, use the tag sql-server instead. "SQL" is an acronym for "Structured Query Language", it is used in relational database management systems (RDBMS) to query, update, delete, and insert data as well as modify the structure of the database. ...

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2
votes
4answers
927 views

search for something in the first 1000 records in the table

If I do the following MySQL query select * from table where name Like '%john%' limit 5; that mean the query will search all the mysql database table and return only the top 5 results that match the ...
2
votes
1answer
3k views

Select the top 5 records and the specific column from each table in the same database

I have 50+ tables in a database. I don't want to use the following SQL on each table in a database. select top 10 * from {table_name} So, is it possible to display the first 10 records PLUS only ...
2
votes
1answer
622 views

SQL INSERT Query takes 2 seconds and sometimes much longer to execute

I know the question's title is bad, But I have an hard time figure it out my self... sometimes this query runs in 2-3 seconds and sometimes it's takes even 30 seconds I have a table named ...
2
votes
2answers
3k views

MySQL case sensitivity for table names

Why is it that different platforms (linux vs windows) does not support the same naming conventions? I'm stunned by the fact that the documentation uses file names as an excuse for this. Yes, windows ...
2
votes
2answers
877 views

How to GROUP_CONCAT between given rows?

I have a table as id diary 1 breakfast 2 walk 3 start 4 office works 5 office projects 6 end 7 taxi 8 start 9 preparing for meeting 10 doing the meeting 11 end 12 night I want ...
2
votes
3answers
14k views

“lock request time out period exceeded” Error When Trying to See DB Hierarchies

I'm having problems with a database. I can run basic queries, albeit much slower than normal. When I attempt to view the hierarchy trees for tables, views, or procedures in SSMS Object Explorer, I ...
2
votes
3answers
2k views

Mirroring Databases in MySQL

Is there a way to mirror databases in MySQL? In SQL Server, you have the ability to link 2 databases in a master to master relationship. One DB will accept transactions and the transactions will be ...
2
votes
2answers
737 views

Design best practices for last tracking with indexed view

My tables structure is below : TbDoc (ID int , ...) TbDocActions( ID Int, DocID Int, Date DateTime, col1 int, col2 int, ...) I want to have indexed view to get last TbDocActions columns for ...
2
votes
1answer
705 views

Change in datatype?

I have a table on which rows are inserted on hourly basis. The row contains id, installation, product_id and hit_allowed. all of them were mediumint in the beginning. but few days back id reached it ...
2
votes
1answer
279 views

Flat query to Column structure

I am trying to structure a query for a calendar view. I want each row to return the details for a person and what they are doing for 7 days (split into AM and PM) So the result set might look like ...
2
votes
3answers
285 views

How to get all non deleted messages from one user

I have two tables one for messages called default_messages and the other for recipients called default_recipient. This is how SQL for those table looks like: CREATE TABLE IF NOT EXISTS ...
2
votes
1answer
143 views

SELECT for values in a table

I have this table structure: id1 id2 1 2 1 3 2 1 2 4 id1 and id2 are not unique as you can see in the values. I need to retrieve those values that exists in the two columns ...
2
votes
3answers
4k views

Easy or Schedulable way to move data from Production to Test

What I am looking to do, is schedule a copy of data from my production database to my dev/test database. The dev/test database will be newer than the production database in terms of schema, but the ...
2
votes
2answers
1k views

How can can I get object definitions stripped of all comments?

When I want to know if a stored procedure or views references a given name (table, view or column), I need a version of the object definition stripped of all comments. Is this possible by a SQL ...
1
vote
1answer
52 views

SSIS Transaction Problem

I am trying to use SQL transaction with my SSIS package so if any error comes changes are rollback. I am using an "Sequence Container" in Control Flow for this and setting its "Transaction Option" to ...
1
vote
1answer
38 views

How to shard a database like that of SO?

I know a bit about sharding but I cannot wrap my head around that fact that say eventually SO cannot scale vertically then how would they shard their SQL DB? Even if we assume SO will not reach that ...
1
vote
2answers
103 views

New to databases - does my ERD reflect good database design?

I'm making a database to hold data for a media player that I'm working on. Originally, I thought to use one table with the fields: {filePath,artist,title,album,track_number,length,date,artworkUrl} ...
1
vote
2answers
431 views

Add function parameter to SQL query WHERE clause

I have a web application in java and it uses a query. I don't want to write the query into Java, so I made a function: CREATE OR REPLACE FUNCTION testFunc(inputs text) RETURNS TABLE(...) AS $$ ...
1
vote
3answers
94 views

Clustered Index improvemens for particular queries

I found a table that looks like this: CREATE TABLE [dbo].Table1 ( id INT primary key IDENTITY (1, 1), [idUser] INT NOT NULL , [Amount] INT NOT NULL , [Attempts] INT NOT NULL , ...
1
vote
1answer
209 views

Fetch data from same table using two group by clauses in mysql

I have one table name as consultant with 4 fields(id, name,user_type, Created date). I need to write an mysql query for return the count of user_type in each month. In my table, user_type is ...
1
vote
1answer
2k views

Efficient way to insert/update/delete table records from complex query in Postgres 9.x

I have this function which returns a set a records and I need to persist those records into a table. I have to do it hundred times a day. My initial approach was just clear data from my table and ...
1
vote
2answers
508 views

How to make a table name an attribute in PostgreSQL?

I have received hundreds of tables in PostgreSQL with identical structure and each containing similar data of a different day, so that the table name is the date of the data. I would like to Union ...
1
vote
1answer
1k views

Very slow simple PostgreSQL query on RDS

I seem to be getting very slow queries on a medium sized RDS box (db.m3.medium, 3.7gb ram). This is across a table of 4,152,928 rows.. select sum(some_field) c from pages where pages.some_id=123 and ...
1
vote
4answers
1k views

Is it ok to change from full recovery to simple recovery in Sql Server

I have an old database - a users membership/role that was setup automatically by an ASP.Net 2 application years ago: The Sql Server version currently running is: Sql Server 10.5.1617 The users ...
1
vote
2answers
65 views

Time elapsed Calculation

I need to calculated time elapsed for each user to perform his part in a transaction. The sequence is: 0 -1 - B2 or 0-B3 The table looks like the following: ...
1
vote
0answers
51 views

Modulus calculation for compound primary keys in MySQL Cluster (and other sharded databases)

In MySQL Cluster, and generally in sharded databases, how is a compound primary key's modulus calculated? Say, for example, there are two tables that have primary keys like so: CREATE TABLE Orders ...
1
vote
2answers
125 views

How to get the first or last row in ordered result set, depending by column value?

I have the follwoing result set from the table PUNCHREPORT EMPLID Name PUNCHDATE PUNCHTIME DEVICETYPE .................................................................. 70 ...
1
vote
3answers
669 views

Building A SQL table horizontally VS vertically

What is a better design principle when designing SQL Server tables. One can either add columns (ie grow horizontally) or grow it vertically (ie rather adding rows) I have a situation when there are ...
1
vote
1answer
207 views

How to speed up looped INSERT INTO statements?

I currently use the following statement, for 10,000 rows it takes about 150 seconds. I tried removing the index on the target table, but this didn't help. Running the loop without the INSERT INTO ...
1
vote
1answer
315 views

Is there any way to get the estimate cost of executing a query in MySQL?

In PostgreSQL, EXPLAIN or EXPLAIN ANALYZE will show the estimate cost of executing a query. But EXPLAIN in MySQL doesn't provide this information. How can I get the estimate cost without installation ...
1
vote
2answers
442 views

How to retrieve the Capture Instance for a given table?

Working with SQL Server 2012, I have a hierarchical table layout (TPT). All tables "inherit" from the same base table (dbo.DataObjects). All tables have history tracking via CDC enabled. I am trying ...
1
vote
1answer
153 views

creating table result in errno 150

I'm trying to create the following schema, but I'm getting errors when I'm trying to create project and staffphone tables. Not sure what is it complaining about. mysql> CREATE TABLE staff( ...
1
vote
1answer
264 views

Self-join unique pairs

I have a table (players) containing a list of players, I would like to pair up these players in a unique way, so that every player's opponent is unique every round (ie. every time the SELECT query is ...
1
vote
0answers
76 views

Efficient way to Add NON-CLUSTERED Index?

I have the following table, CREATE TABLE [dbo].[Products]( [ID] [int] IDENTITY(1,1) NOT NULL, [RetailerID] [int] NOT NULL, [Name] [nvarchar](255) NOT NULL, [Price] [float] NULL, ...
1
vote
1answer
96 views

How does the transactions interact if you set a different isolation level per connection?

I read that I can have different isolation levels per connection and in the server. The default isolation level is REPEATABLE-READ. So if I have a transaction that issues a SERIALIZED to the client ...
1
vote
1answer
145 views

Optimizing Postgres query

I've got a one to one relation from users to addresses table. Where one user can have one search address and one verified address. I've got two indexes on addresses table : Index on state field ...
1
vote
0answers
265 views

Missing rows in MyISAM tables with 10-20 billion records

I've got 2 tables with 10-20 billion records each. Currently these are in MyISAM (MySQL). They only require to be built and indexed once, after this only SELECT is used. They are currently ...
1
vote
4answers
124 views

Amount of data in a database table

I am trying to run an alter query on a table, and its giving me a Lost connection to MySQL server during query MySQL server has gone away. The query that I am running is alter table table_name ...
1
vote
1answer
346 views

Slow queries related to subqueries using aggregation

Here's a simplified version of the queries I am running: select ... from editions join edition_events on edition_events.edition_id = editions.id join events on events.id = ...
1
vote
1answer
158 views

SQL Server log file continues to grow? [duplicate]

I'm having an issue with a SQL Server log file which will not maintain a steady amount of space held on a HDD which it has been issued. The drive is ~50GB and the log file is growing to occupy this ...
1
vote
2answers
2k views

Optimizing removal of duplicate rows from recursive CTE query

I need to write a recursive SQL query to fetch multiple projects together with their lineage from the following table: CREATE TABLE #Project ( Name VARCHAR(10), ParentName VARCHAR(10) ) INSERT INTO ...
1
vote
1answer
514 views

counter table in mysql

i was going through the book: High performance MySql 2nd edition. In chapter 4 it says: An application that keeps counts in a table can run into concurrency problems when updating the counters. ...
1
vote
1answer
2k views

Is there a way to determine automatic storage table spaces?

First off, we are on both Windows and AIX and are using DB2 ESE 9.7 FP 4. I am trying to determine dynamically whether or not table spaces are set up via automatic storage or not (so we can ...
1
vote
1answer
227 views

Relative cost of two similar queries involving XML columns

I have two queries as shown below which do the same thing. Here xmlcolumn is a column with datatype XML. I use these queries to search for a string anywhere in the XML column. I checked the execution ...
1
vote
1answer
1k views

Upgrade SQL Server 2005 Enterprise to SQL Server 2008 R2 Standard

I understand that this is not a supported path, but does anyone have any insight about how to accomplish this? I can't seem to find any documents on the subject. I need my QA (2005) to match my ...
1
vote
2answers
2k views

Get all partition names for a table

I want to list all the partitions created by dynamic triggers in PostgreSQL 9.1. I was able to generate a count of partitions using this related answer by Frank Heikens. I have a table foo with an ...
1
vote
2answers
418 views

How to link each column in sql?

I have been working around on a query given by one of my developers who works on crystal reports as a junior DBA, I always like to help them even though I am busy with other things as it will increase ...
1
vote
1answer
7k views

Connect Error (2054) - mysql_old_password issue still not solved

i use php 5.4.3 and i want to connect to a MySQL DB remotely (php script resides on a different server than the db) with normal oop way: $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME); ...
1
vote
2answers
1k views

Factoring out subselect (with clause) ends in ORA-00904

I am trying fo factor a repetitive subquery with with but getting ORA-00904 over and over again. This is my base query which works quite well: select tka.id, tka.name, txt.text as langname, ...
1
vote
2answers
1k views

ERROR: could not find array type for datatype information_schema.sql_identifier

I am trying to run the below sql command: SELECT ARRAY( SELECT column_name FROM information_schema.columns WHERE table_name ='gis_field_configuration_stage' ); and I get the below ...