Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [derby]

Apache Derby, an Apache DB subproject, is an open source relational database implemented entirely in Java and available under the Apache License, Version 2.0.

Apache Derby

  • Derby has a small footprint -- about 3.5 megabytes for the base engine and embedded JDBC driver.
  • Derby is based on the Java, JDBC, and SQL standards.
  • Derby provides an embedded JDBC driver that lets you embed Derby in any Java-based solution.
  • Derby also supports the more familiar client/server mode with the Derby Network Client JDBC driver and Derby Network Server.
  • Derby is easy to install, deploy, and use.
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What are the drawbacks with using UUID or GUID as a primary key?

I would like to build a distributed system. I need to store data in databases and it would be helpful to use an UUID or a GUID as a primary key on some tables. I assume it's a drawbacks with this design since the UUID/GUID is quite large and they…
Jonas
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Does making a field unique make it indexed?

If I make a unique constraint on a field, do I also need to make an index on that field in order to get a scalable insert time? Or is this done for me (even if the index it uses isn't publicly accessible?) Specifically, I'm working with Apache Derby…
corsiKa
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PostgreSQL "freeze"/"unfreeze" command equivalents

In Derby (an embedded database written in Java which is mostly used for testing or prototyping) there are "freeze" and "unfreeze" commands which can be used during an online backup. "Freeze" simply causes all database accesses to block until…
Dan
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Derby slows down after 1.2 million records

I'm using a Derby database, mass insertions slow down to 1/4 to 1/6 the speed once there are 1.2 million records (about 6 GB database size, one major table, other tables are tiny). Is that normal? Is there something I can do to tweak it and make it…
Mary Aubaun
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Are there any good database management applications for JDBC/Java databases?

I am working with an Apache Derby/JavaDB database via JDBC. Before have I been working with MySQL and used phpMyAdmin as a good Database Management tool. Is there any good desktop application for managing databases over JDBC?
Jonas
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Building a tree in Apache Derby 10.10

I know this question has been asked probably a million times, so please forgive me asking it again. I am not a DBA and have very little knowledge of SQL and Derby, but need some kind of a solution as I am the only one responsible for getting this…
kooker
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Convert Oracle database to Derby

I need to migrate an existing Oracle Database into a Derby one. I want to know if there's a tool, a script or another way to do that work. It is using any of the interesting features of Oracle, as I can see from the database information from SQL…
Yann Tombmyst Tremblay
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Two different ON DELETE paths, how do I need to change the schema?

For a project in school I'm designing a website that sells items via auctions. Think eBay, but on the complexity scale of school project. We went through the process of making an ER Diagram and planning things out but we still ran into a snag with…
Huckle
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Long JOINS Returns No result all tables have one to many relationship with a particular table

I have a Table Enterpries with Primary Key 'RCNO'. All other tables have a one to many relationship with Enterprise via it's RCNO column. I make a Join of all the tables and i get nothing. Below is the query. I would like to attach the tables(sql).…
M.Hussaini
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Please explain SYSCS_UTIL.SYSCS_CREATE_USER() function

Can someone please explain to me how SYSCS_UTIL.SYSCS_CREATE_USER() works? I tried adding a new user like this: SYSCS_UTIL.SYSCS_CREATE_USER('user', 'someP@ss'), and it gave an exception Error code 30000, SQL state 4251K: The first credentials…
Johan Brink
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Derby/SQL - How to increase performance when left joining and retrieving varchar columns

Through trial and error I found that if I do a left join such as: SELECT firsttable.id, secondtable.id, secondtable.varcharColumn FROM firsttable LEFT JOIN secondtable ON firsttable.id=secondtable.id The performance is…
Stephane Grenier
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Will Derby, H2, or SQLite give faster load time and/or smaller file size than HSQL?

I have some flat files with the following columns; 3 integers, 3 reals, and 1 varchar(20). For querying I need an index that contains both 1 of the integer columns and the varchar column. Each file is around 1.8GB in size with around 38 million…
Edmund
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How to list known users on Apache Derby server?

In the documentation to Apache Derby I've seen documentation on functions to administrate user accounts. However, I did not manage to find documentation on how to get a listing of all registered users. After failing to find a respective answer on a…
jf1
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How to export tables from Derby to SQL Server

How to export tables from Derby to SQL Server? Is that possible?
Mars
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Isn't a PK automatically a proper unique indexed key

I'm checking out some newish features of Apache Derby for my Java EE app. IntelliJ provides helpful shortcuts for creating a simple DB schema. After a few clicks I have create table "Names" ( id int generated always as identity …
Captain Giraffe
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