Stack Overflow
Stack Overflow

Questions tagged [database-engine]

57 questions
172
votes
9 answers

How to write a simple database engine

I am interested in learning how a database engine works (i.e. the internals of it). I know most of the basic data structures taught in CS (trees, hash tables, lists, etc.) as well as a pretty good understanding of compiler theory (and have…
a_m0d
  • 12,034
  • 15
  • 57
  • 79
75
votes
3 answers

What are MySQL database engines?

I looked around and found some of the MySQL engines are innodb and MyISAM. Perhaps there are few more. My question is what are these database engines? What are the differences between different MySQL engines? And more importantly, How do I decide…
pavanred
  • 12,717
  • 14
  • 53
  • 59
7
votes
1 answer

MySQL InnoDB: Differences between WAL, Double Write Buffer, Log Buffer, Redo Log

I am learning MySQL architecture. I come up with the following illustration: There are 4 concepts that I don't understand well: double write buffer log buffer write-ahead log redo log I read from many documents, Write-Ahead Log (WAL) is a…
Trần Kim Dự
  • 5,872
  • 12
  • 55
  • 107
6
votes
1 answer

MySQL database size estimation

I have an application database with a table for users (1kbyte of data per user based on counting fields * typelength), and about 100 things of the same size belonging to a user (0.5 kbyte per thing), and it is in a "user" table and a "thing" table.…
Jay Godse
  • 15,163
  • 16
  • 84
  • 131
5
votes
1 answer

Which database storage-engine is best for implementing a blog?

Possible Duplicate: MySql: MyISAM vs. Inno DB! I am implementing a blog in php using MySql. Not all engines support special field types, as BLOB (binary large object) or TEXT types, which I need to use a lot. Furthermore I will heavily need to…
Matteo
  • 7,924
  • 24
  • 84
  • 129
5
votes
2 answers

What is the difference between SQL Server Compact Edition and SQL Server Express Edition?

Can someone please explain what is the main difference between SQL Server Compact Edition and SQL Server Express Edition? For what purpose I should use this or that one? Thanks
pencilCake
  • 51,323
  • 85
  • 226
  • 363
5
votes
1 answer

Single user database vs multi-user database

What is the difference between single user database and multiple user database? Why I would need to use a single user database? why it was made? If I have multiple threads accessing the same database on the same time using the same log-in…
Costa
  • 3,897
  • 13
  • 48
  • 81
4
votes
4 answers

Error 945 Database cannot be opened due to inaccessible files or insufficient memory or disk space. See the SQL Server error log for details

While trying to access databases, logins, etc in SQL Server Management Studio 2008 R2, below error is always popping up. I browsed over google to find out a solution but those resolutions did not solved below issue. I have sufficient permissions and…
Zakir HC
  • 262
  • 2
  • 4
  • 18
3
votes
2 answers

Optimal Data Storage for Web Analytics

I would like to write a custom web analytics and action tracking solution and use it as a feedback mechanism eg. for searches or content suggestion. If it were only for short lived data, I would use some NOSQL engine with a limited data retention. …
Martin
  • 243
  • 3
  • 16
2
votes
1 answer

MySQL structure for personalized users access per site?

I need some help to structure some tables that will help me out having a good personalized way to have different access name per client with personalized allowed commands in each acess level. So consider client A has create site Y, which he wants to…
Prix
  • 19,417
  • 15
  • 73
  • 132
2
votes
2 answers

How to enable FEDERATED Engine in MySQL?

I installed a new instance on MySQL 5.7.6 on a Windows 7 Laptop. I need to enable FEDERATED Engine on it. in the [mysqld] section I added FEDERATED but when I try to start the server I get error. Here is what mysql error logs show that --FEDERATED…
Junior
  • 11,602
  • 27
  • 106
  • 212
2
votes
1 answer

Why mysql "ENGINE=InnoDB" doesn't work with joomla 3 installation

I got the solution for joomla 3 installation problem(installation stucks in creating databases) in stackoverflow. The solution that to replace "ENGINE=innoDB" with "ENGINE=MyIsam" in joomla-folder\installation\sql\mysql\joomla.sql, it works…
Muthu kumar
  • 162
  • 1
  • 2
  • 12
2
votes
5 answers

sqlerrorColumn 'tableName' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause

I have three tables Table 1: tblCustomer CustomerID CustomerName 1 ABC Bank 2 Chase Bank Table 2: tblOrderType OrderTypeID OrderTypeName 1 Assignment 2 LienRelease Table 3: tblOrder OrderID CustomerID OrderTypeID LoanNumber 1 1 1 …
user3827642
2
votes
2 answers

Why would innoDB lock tables

I'm using innoDB on AWS. I keep getting a ton of the following messages in my logs: Waiting for table level lock I thought innoDB only did row-level locks. I don't have any lock tables in my code. Does anyone have any idea why this would happen?
Andrew Sparrow
  • 167
  • 2
  • 2
  • 12
2
votes
2 answers

How I can find out if the engine of a MySQL database is MyISAM or InnoDB in file system?

How I can find out the MySQL database engine in the file system (data structure, no MySQL commands possible)? It would be nice if you can help me. Best regards, Jonniboy
Jonniboy
  • 136
  • 1
  • 13
1
2 3 4