Tagged Questions
0
votes
1answer
29 views
“relation does not exist” trying to import mysql dump into postgres
environment:
ubuntu 10.04
mysql server 5.1.69
postgres 9.2
Here's the sequence of steps:
created a new postgres database, myDatabase
executed this command: mysqldump -u root -p ...
1
vote
4answers
154 views
Daily and Differential Backups
Is there a program with which I can create daily MySQL, PostgreSQL and MariaDB backups with these requirements:
The first time, make a full backup.
The second time, only the changes since the last ...
0
votes
0answers
36 views
Backup daily for MySQL, MariaDB or PostgreSQL [duplicate]
Good day:
I wonder if there is a program with which I can create daily backups with these requirements:
The first time, make a full backup.
The second time, only the changes since the last backup, ...
1
vote
4answers
129 views
Database design - People and Organisations
Databases are not my primary skill and I am finding I need some assistance please.
The software we are building has "Customers".
The Customer could either be a Person or an Organisation.
I really ...
0
votes
0answers
89 views
Performance difference between MySQL and PostgreSQL for the same schema/queries
I'm a newbie DBA, and I have experience in Microsoft SQL Server but I want to jump to FLOSS.
I'm starting a company, and we develop an app (PHP) with a Postgres backend, and we did some tests ...
1
vote
1answer
51 views
Equivalent of MRG_MYISAM in databases other than MySQL? [closed]
Does anyone know if other database have something equivalent to MRG_MYISAM (aka the MERGE table type/storage engine)?
I know about fragmenting, but this is not quite the same AFAIK. We're using ...
0
votes
1answer
107 views
Object-oriented programming CRUD design pattern
At first I have posted this question at http://cstheory.stackexchange.com/questions/17170/object-oriented-programming-crud-design-pattern - that's because I think it's a subect question, and it can ...
1
vote
0answers
25 views
MySQL Federated acces to PostgreSQL table
For example 2 DBases:
DBMS Postgresql
DBMS MySQL
In each DB include one DB and one table in it. Can I work with table in PostgreSQL through MySQL?
Is it possible to link as federated postgresql ...
0
votes
0answers
123 views
Achieve PostgreSQL hstore functionality in MySQL
Please suggest any MySQL 5.5+ Engine that can support collection of key-value pairs be stored in any column of a table.
I don't know if this feature is available out of the box in MySQL like ...
0
votes
1answer
95 views
multi-master to single-slave replication at table level with PostgreSQL or MySQL
Here is my scenario
Master1 hosting DB1
Master2 hosting DB2
...
MasterN hosting DBN
replicate to:
Slave1 hosting DB1,DB2... DBN
I've read similar questions and they recommend to start different ...
4
votes
1answer
245 views
Is PostgreSQL replication production ready?
How does PostgreSQL native replication compare to MySQL?
I know asynchronous replication has been supported for longer than sync, which is recent. Is synchronous reliable to be used in real projects?
...
1
vote
1answer
158 views
Efficient query plan for selecting all data duplicated on several columns
The flavour in question is PostgreSQL, but it is a generic enough query pattern that your techniques for optimising against other RDBMs should help as well.
The purpose of the query is to show all ...
1
vote
1answer
164 views
Which Database to choose: MySQL or Oracle
I have an application generating time series data (32 channels, 22KHz, 6 secs) once a minute. These have to be stored in a database. At the moment I'm using MySQL with InnoDB tables ...
0
votes
1answer
161 views
Storing 5TB web server access log vs OLAP DB
We have over 5TB compressed web server log in a HDFS and we often analyse using Hadoop.
It is painful to run map reduce on 5TB of data and most importantly, not many developer are familiar with it.
...
0
votes
2answers
139 views
Why do people use MySQL while it has no INTERSECT? [closed]
I see that PostgreSQL is being developed, for example it has INTERSECT and JSON types. Why MySQL is not being developed? Why people use MySQL over PostgreSQL. What I'm missing?
4
votes
1answer
120 views
Do isolation levels only apply to SELECTS and not UPDATES? [closed]
Scenario that might demonstrate different behavior for SELECTS depending on the isolation level:
1) 0:00 Thread A runs a query that returns 1000 rows that takes 5 minutes to complete
2) 0:02 Thread B ...
3
votes
2answers
219 views
SQL ANSI JOIN precedence
I have a query that looks like this:
SELECT *
FROM TBLA A
LEFT JOIN TBLB B ON A.Col1 = B.Col2
RIGHT JOIN TBLC C ON B.Col3 = C.Col4
JOIN TBLD D ON C.Col5 = D.Col6
In which order ...
0
votes
2answers
74 views
How to remove tables and indexes?
I've a file with the SQL statements to create tables, indexes, etc, and another file with data test to use in the test database. Then, I want that they can be removed.
How to remove table and indexes ...
6
votes
2answers
986 views
For absolute performance, is SUM faster or COUNT?
This relates to counting the number of records that match a certain condition, e.g. invoice amount > $100.
I tend to prefer
COUNT(CASE WHEN invoice_amount > 100 THEN 1 END)
However, this is ...
3
votes
5answers
1k views
Alter table on live production databases
How do most "popular" (MySQL, Postgres...) database system handle altering tables on live production databases (like adding, deleting or changing the type of colums)?
I know the correct way is to ...
3
votes
1answer
136 views
Model with variable number of “properties” of different types.
I would like to have a table of microscope slides, where on top of the basic id, name,date_created would each slide also have a number of editable "properties".
Imagine one slide having
...
1
vote
1answer
1k views
Scalability limitations of PostgreSQL and MySQL
I've heard that performance of non-sharded relational database such as MySQL or PostgreSQL "breaks" beyond 10 TB.
I suspect that limits as such do exist as one would not come up with Netezza, ...
-1
votes
1answer
219 views
Database for an application similar to Chatroulette
I am making an app that is similar to Chatroulette.
When a user starts the app it finds someone that is not currently talking to anyone and have them talk to each other. At any point a user could ...
3
votes
1answer
1k views
PostgreSQL 9.1 vs MySQL 5.6 with InnoDB ? Which is better for scaling?
PostgreSQL 9.1 vs MySQL 5.6 with InnoDB. I do know that PostgreSQL offers better SQL features.
I am currently using MySQL 5.6 lab release (the one with InnoDb full text search feature)(not in ...
2
votes
2answers
216 views
MySql Vs. Postgresql for a blog application
I am designing a blog application. Which of these fits better?
In which use cases will mysql be good and for what use cases will postgresql be good?
9
votes
1answer
266 views
Disable explicit commits in JDBC, detect them in SQL, or put the database in a readonly state
Background: I'm working on http://sqlfiddle.com (my site), and am trying to prevent one avenue of abuse possible there. I'm hoping that by asking about a problem I'm currently addressing, I don't ...
3
votes
2answers
159 views
Migrating and normalizing data
We are rewriting a large Django application which uses a MySQL database, and the database schema needs to undergo major modifications. We're also porting the app to use PostgreSQL, for a couple of ...
0
votes
2answers
262 views
Creating a test database from Production database (different machines & servers)
I'd like to set up a test database on a separate server. Production database is MS SQL Server and the test server is a *nix box so I'd like to have the test server running either PostgreSQL or MySQL.
...
3
votes
2answers
637 views
Can I have one table be an “alias”, or “symlink”, to another?
I have two tables with the same structure, A and B. A certain application is written so that it always writes the same data to both tables.
After a discussion with a colleague about the potential to ...
1
vote
1answer
376 views
PostgreSQL vs MySQL benchmarks when a 2nd level cache is included
Has anyone been able to find any benchmarks comparing PostgreSQL and MySQL performance when they are used by a system through Hibernate (or another comparable ORM) and the 2nd level cache (backed by ...
2
votes
2answers
1k views
How to convert PostgreSQL to MySQL
How can I convert database from PostgreSQL to MySQL?
I have the postgresql dump file already and I try to use pg2mysql script, it converted but when uploading the file it produces this error:
ERROR ...
11
votes
3answers
2k views
Is the CPU performance relevant for a database server?
This is a purely theoretical question. Let's say I have an application deployed on multiple servers.
A load balancer,
Multiple/scalable applications servers
A (single) database server (for the ...
-1
votes
1answer
263 views
Important distinctions between DBMSs [closed]
DBA is a career I'm strongly considering after school, but my limited experience mostly involves some PL/SQL Oracle web programming, some basic PHP/MySQL web pages, and some queries in SQL Server. ...
4
votes
3answers
530 views
How can I write a proper query to JOIN all of these tables without duplicates?
Let's say I have four tables:
TABLE: players
COLUMNS: id, first_name, last_name
TABLE: passing_stats
COLUMNS: id, year, passing_yards (several other passing columns)
TABLE: rushing_stats
...
1
vote
2answers
1k views
Request suggestion for a database between MySQL and Postgresql
We maintain a list of all the SAN Switch Ports that are either free or allocated to hosts. Currently, we enter the information on the company portal. But we need to move if off to a database because ...
1
vote
3answers
1k views
How to convert a MySQL database to PostgreSQL?
Is there any command line tool for converting the MySQL database to PostgreSQL? I'd also like to know if there is a way to convert the database using the normal mysqldump command.
6
votes
2answers
600 views
Database for building a realtime analytics system
I want to build a system similar to Google Analytics (only used for internal use, less traffic and less feature), and mainly focus on
Real time counting of unique URI visit/PV by different ...
8
votes
2answers
3k views
PostgreSQL vs. MySQL - Advantages / Disadvantages with a spatial component
We are the in the process of building out a web application that has a spatial data component. In the beginning our spatial data comparisons will take a given point and return matched overlapping ...
5
votes
3answers
2k views
How to convert mysql to postgresql?
I am desperately looking for a conversion tool to convert a big mysql database to postgresql. I need the tool/script to be:
Free
Works under Linux
Simple to use and not buggy
You actually tried and ...
3
votes
1answer
639 views
Database as a service (DbaaS) over dimensions--performance, scalability, & reliability?
MySql Database as a service:
Amazon
Xeround
Another eg. PostgreSQL Database-as-a-Service.
You can get the list of similar products here.
Does anyone have details on their performance, ...
3
votes
2answers
2k views
No NULLs, yet invalid byte sequence for encoding “UTF8”: 0x00
I've spent the last 8 hours trying to import the output of 'mysqldump --compatible=postgresql' into PostgreSQL 8.4.9, and I've read at least 20 different threads here and elesewhere already about this ...
3
votes
4answers
3k views
Visualization of MySQL/PostgreSQL table structure as a graph/UML
Is there any program, source code or API that will take a MySQL or PostgreSQL schema and
spit out a UML or some other graph visualizing of it?
6
votes
2answers
845 views
Is DB2 more reliable and stable compared to PostgreSQL or MySQL?
Always i was using MySQL or PostgreSQL for my projects such as Web/Desktop apps.
I had data loss few times and thanks to old backup i was always up and running.
But for a recent project for Airport, ...
1
vote
1answer
427 views
storing a mirror of IMAP/pop3 folder/inbox in a local DB, what choices are there?
I have a email inbox that will soon hit 4 million messages, I have an app that runs different policies over the inbox to associate emails with each other much like the conversation plugin for ...
3
votes
1answer
297 views
Solution for deploying multiple instances of Django Server with Database replication
have written a Django application that reads / writes data into a postgres database, at the moment I have been deploying one of these devices per client. I am faced with having to deploy multiple ...
14
votes
2answers
4k views
Find highest level of a hierarchical field: with vs without CTEs
note: this question has been updated to reflect that we are currently using MySQL, having done so, I would like to see a how much easier it would be if we switched to a CTE-supporting database.
I ...
4
votes
2answers
208 views
What is the consensus on using NOT NULL constraints on all text-based fields in a table?
Some of the tables I have come across don't have any NOT NULL constraints, which has yielded to some gotchas when querying.
I'm curious what the feelings are with using something like NOT NULL ...
6
votes
3answers
297 views
Is there a need to keep refreshing the indexes from time-to-time?
This question is common for all the database products I use, viz. SQL Server, MySQL, Oracle and PostgreSQL.
I have created a fresh database and the tables, at present, have no records. I have created ...
2
votes
2answers
312 views
Database Transfer from PostgreSQL to MySQL
Is there any method to tranfer the data and schema from a postgresql database to mysql?
2
votes
1answer
342 views
What are the pro's and con's of using PostgreSQL vs MySQL for binary data?
I read that MySQL has binary safe blobs, but PostgreSQL does not.
So far what I've found suggests that "binary safe" is something that really relates to functions and handling of data, not the data ...
