6
votes
1answer
748 views

How to find MongoDB index statistics

Is there any way we can figure out what all indexes are cached into RAM ? I want to know page related stats for individual indexes (# of hits and miss )
2
votes
1answer
5k views

How do you setup a new oracle instance from the commandline after having done a database software only install?

I'm trying to familiarise myself with the process for setting up new instances/databases from the commandline with the aim of building a tool for deploying databases. The process we are thinking of ...
0
votes
3answers
79 views

Should frequently accessed tables containing large blobs with one-to-one relationships be normalized and columns split into two tables?

I have a frequently accessed table containing 3 columns of blobs, and 4 columns of extra data that is not used in the query, but just sent as result to PHP. There are 6 small columns (big int, small ...
0
votes
2answers
684 views

Postgres 9.2 - Create View Different Column Names

I want to create a view of a table with a column renamed. I do not want to effect the source table, just the view. I need to rename the column addr:housename to addr_housename. We have a 3rd party ...
4
votes
2answers
4k views

I dropped MySQL's `performance_schema` database, how can I create it?

While fixing a ibdata/log problem, I accidentally dropped my performance_schema database, I'd like to create a new one. mysql> SHOW VARIABLES LIKE 'perf%'; +----------------------------------------...
0
votes
0answers
2k views

Oracle profile: PASSWORD_REUSE_TIME and PASSWORD_REUSE_MAX

Let's say I have configured PASSWORD_REUSE_TIME=1 and PASSWORD_REUSE_MAX=5 for Orale user profile. My initial understanding was that it should prevent the user from using the same password until he ...
1
vote
2answers
3k views

MySQL: How to drop all tables starting with a prefix?

In my database there is a lot of tables starting with _elgg , now I want to drop all tables with this prefix. Can anyone give me a solution ? Thanks in advance!
0
votes
1answer
53 views

How to find a session with a specific command

I have an Oracle instance with some active sessions from different users. How can I find the SID/SERIAL of a specific session given that this session is surely running a specific SELECT I know?
1
vote
1answer
673 views

how does multiple column index work in details

if we have a table T1 with columns A,B,C,D,E and an index ( A,B,C) built for it if we a SQL query joining on columns A,B or A,B,C or A, this index can still be used, but if the query is joining on B ...
1
vote
1answer
618 views

Appending imported data in Postgres

This is what I typically use to import csv data into my postgres database.. \COPY master_list FROM '/root/raw/file.txt' DELIMITER ',' CSV; Usually it's into a blank table, but in this case, I need ...
0
votes
2answers
386 views

Does Oracle RAC require that the Ethernet aliases be in a different IP range than the base addresses?

Let's say I have 3 nodes running RAC. The base addresses (eth0 interfaces) for those nodes are in the 192.168.1.0/24 range. From what I've seen RAC requires that you create Ethernet alias interfaces (...
1
vote
2answers
833 views

How much RAM should you allocate a MySQL replication slave?

Our MySQL master is allocated 24GB of RAM (innodb_buffer_pool_size = 24GB), but was curious if there was some standard amount to allocate to a replication slave? Right now the slave is just used to ...
0
votes
1answer
2k views

SQL Server to MySQL sync, using Workbench, FreeTDS, and iODBC on 10.9

I've been struggling to get the MySQL Workbench to behave properly to complete the following: With Mavericks (OS X 10.9), connect to a SQL Server and create a migration job to a MySQL server. The ...
0
votes
2answers
97 views

General ETL principle - ETL from unknown number of tables? [closed]

AFAIK, ETL integrates data from a fixed number of sources/tables. Is it possible that ETL can integrate data from an unknown number of tables which might be added in the future, given that these ...
0
votes
2answers
92 views

Is my JOIN syntax not valid? And have I understood JOIN correctly?

I've been reading up a bit regarding JOINs. And i just noticed that I've been writing the syntax a little bit different. Although I don't think there's any problem with it, I would like to hear your ...
3
votes
2answers
4k views

MySql InnoDB tables are missing after restarting

I had a MySql database with a few InnoDB tables. After restarting the server, and starting MySql Server again, I connected to the MySql Server using MySql Workbench, and couldn't see the database at ...
0
votes
0answers
88 views

Order before Group

I have this query: SELECT HOTEL.hotelname AS NAME, HOTEL.`boardbasis` AS board, HOTEL.`engine`, HOTEL.`itemcode`, Group_concat(Round(((hotel.cheapestprice / 2) + flights.price)...
1
vote
1answer
950 views

Oracle OS Authentication only works on certain databases/clients

We currently face a problem where Oracle OS authentication only works on certain client/server combinations. The environment consists of a development client with its own database server (excluded ...
1
vote
1answer
589 views

Does MySQL load the entire row into memory, or just the columns used in WHERE, ORDER BY and GROUP BY?

I have a table that isn't very large row wise (in the 100ks range), but that contains a lot of raw data that is very large in size. Despite having a relatively little number of rows, it's around 1.5GB....
1
vote
2answers
89 views

Profiling feature for SQL server 2012

I'm using SQL Server 2012 to develop php/web applications. On my development machine, I have SQL server also. The php codebase is version controlled with git. The various applications we have (and ...
0
votes
1answer
963 views

Sync offline PostgreSQL server

I am new to PostgreSQL. I am looking for a solution wherein 2 mirror images of a database sit on a local and remote server. All the work is done on the local server and at periodically synced with the ...
0
votes
1answer
291 views

How to UPDATE MAX and MIN of a GROUP BY?

I have a SELECT query of a table with GROUP BY id col1 category 1 some 1 2 x 1 3 another 1 4 x 2 // should be removed 5 some 2 6 x ...
0
votes
1answer
663 views

Taking hot backup of slave node in postgres (master-slave config with repmgr)

I have a postgresql setup with master-slave configuration using repmgr. I'm struggling with taking a consistent snapshot backup (pg_start_backup) of the slave node, this is due the fact that the slave ...
5
votes
1answer
551 views

Disabling SET Statements / Forcing SET Options in SQL Server 2008R2/2012

I am currently working with a MSSQL 2008R2 Database which uses the following SET-Commands frequently: SET ANSI_NULLS { ON | OFF } SET QUOTED_IDENTIFIER { ON | OFF } SET ANSI_PADDING { ON | OFF } ...
2
votes
1answer
152 views

PL/SQL doesnt return rows

Please help me debug this: Working: When I execute: set serveroutput on declare middle_name varchar2(30); begin middle_name := '0000000231'; for x in ( select ...
3
votes
0answers
18 views

Disabling SET Statements / Forcing SET Options in SQL Server 2008R2/2012 [duplicate]

I am currently working with a SQL Server 2008 R2 database which uses the following SET commands frequently: SET ANSI_NULLS { ON | OFF } SET QUOTED_IDENTIFIER { ON | OFF } SET ANSI_PADDING { ON | OFF }...
5
votes
1answer
917 views

AWS RDS showing large growth in Write Ops/sec, despite low # DB connections?

I have a Multi-AZ AWS RDS instance running MYSQL 5.5 I've noticed that my write ops/sec are growing fairly rapidly, despite low (and sometimes zero) DB connections - see charts for Avg write ops/sec ...
0
votes
2answers
715 views

MYSQL - Why does this SELECT get slower the further down the table?

My table: CREATE TABLE `wp_users` ( `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `user_login` varchar(60) NOT NULL DEFAULT '', `user_pass` varchar(64) NOT NULL DEFAULT '', `user_nicename`...
0
votes
1answer
662 views

Use string functions and arithmetic calculations in SQL query or by programming language?

I need heavy arithmetic and string functions for processing the data captured from mysql database. Which is preferred: mysql functions or programming language (e.g., PHP)? $result = $mysqli->query(...
3
votes
1answer
340 views

PostgreSQL: When should I use fillfactor < 100 for tables on SSD?

PostgreSQL documentation says that choosing smaller fillfactor lets table reserve space for future updates on the same page and "This gives UPDATE a chance to place the updated copy of a row on ...
-1
votes
1answer
1k views

Will the indexing affect insert/update/delete operation in Mysql [closed]

Will the indexing affect insert/update/delete operation in Mysql 5.1 Will it take down performance of insert update delete operations, If yes, why it will happen so. So are indexes always meant for ...
0
votes
2answers
4k views

How to convert SQL Server database file to MongoDB? [closed]

I have .mdf / .sdf files created in SQL Server. I want to convert them to MongoDB. How can I do this?
2
votes
3answers
3k views

How to remove master role from MySQL server

I have 2 MySQL servers, one is the master and other one is slave, that's all good. The problem I have is that the slave is also set up as a master. I would like to disable or remove the master role ...
1
vote
3answers
140 views

How to map similar camelcased, pascalcased, underscored, lowerscored words to the same id?

I'm working on PostgreSQL and I have a table like this called words_table: I need all equivalent words (like software_design and software-design) to have its map value = to its word's equivalent ...
4
votes
1answer
2k views

Why does implicit conversion from sql_variant (basetype decimal) not work well with float

Why is ResultFloat = 0 in the query below? Am I missing a point within the cast/convert, sql_variant docs? declare @v sql_variant = convert(decimal(28,8), 20.0); select sql_variant_property(@...
2
votes
1answer
46 views

General purpose view for last value in a group

I am trying to create a view to show the last value in the group. Looking for a more general purpose query. CREATE TABLE a ( id INTEGER, seq INTEGER, val VARCHAR2(16), PRIMARY KEY(id,seq)...
1
vote
3answers
11k views

Select query to retrieve values even if are null

I need some help in a query. Need to retrieve data from 1 table, even if one of the field has null value. Here's an example: Select name, SUM(credit) as credit From expenses Where name like 'vendor0%'...
4
votes
1answer
1k views

How to replace “set rowcount”

Currently on SQL Server 2008/R2. I just read here that "set rowcount" is being deprecated in some post 2012 release: http://technet.microsoft.com/en-us/library/ms188774.aspx We have some legacy code ...
0
votes
2answers
197 views

In Oracle, why would an OR / LIKE(A,B) take far longer than running the same query for each condition separately and unioning

I have a complicated subquery that looks something like this SELECT ... FROM ... WHERE my_column IN (1,3) It takes a long time to run. I tried splitting it out into: SELECT ... FROM ... WHERE ...
0
votes
0answers
636 views

Can an SSIS variable have a default value?

I have to migrate a SQL Server 2000 database to version 2008. A large part of that work is to update all the DTS packages to SSIS. Many of the packages require using the current date to establish ...
5
votes
2answers
7k views

Issues with TempDB mdf file ever increasing

I have a tempdb growth issue. Let me preface everything by giving my tempdb settings. Even with no queries running on the database/server tempdb keeps on increasing in size, at first rapidly and ...
1
vote
0answers
3k views

ERROR 17058 COULD NOT FIND THE ERROR LOG

We just installed SQL Server on 1st node of windows cluster and it stop/start fine from configuration manager but from command line it is giving error and I checked that service account have all the ...
1
vote
1answer
694 views

How to perform a multiplication by a different select query

Hope my question is accepted here and I haven't made a mess out of renaming the tables and columns so you can understand what I need! :) Query A: DECLARE @var VARCHAR(7) SET @var = 'xtpo' SELECT ...
18
votes
1answer
1k views

24x7 vs Night Time Window

Where can I find resources on how to better move to a 24x7 operation? How do the big companies with big databases accomplish this? Our nightly jobs such as purge old data reindex update ...
0
votes
1answer
158 views

How can I normalize this database?

I've got legacy ecommerce database, which is awfully designed and I need to move all products from it to new solution. But I stuck with how product properties stored. So it basically has tens of ...
4
votes
1answer
944 views

Determine the currently executing statement in a long running PL/pgSQL stored procedure

I have a long running PL/pgSQL stored procedure in PostgreSQL. How can I determine the currently executing statement in it?
0
votes
1answer
92 views

Performance on updating row

When updating in SQL Sever, it is my understanding that the entire row is deleted and then recreated (which is why you get a new timestamp). So then, if you update 1 field or 500 fields, does the ...
0
votes
3answers
262 views

From freelancer to team of two : best way to share/sync db?

I am a webdev. I have just hired a dev. Before that I was alone. Thus, I have to change a bit my organization. I am looking for the best way to develop on the same database (MySQL). I am considering ...
1
vote
1answer
2k views

Mysql Innodb as Key value store, performance

I read about NoSQL databases using Key value pairs (KVP) tables. So i wanted to find out if KVP tables would be faster than conventional relational tables (with multiple columns) in mysql with innodb ...
4
votes
1answer
175 views

MS SQL Server using SSL Connection over the Web?

I'm looking to have an external SQL Server 2008R2 Express instance and be able to connect to this via SSL using a 'sql.my-domain.com' address. So far, I've looked at a few Microsoft links on the ...

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