0
votes
1answer
79 views

Why can't modern databases have unlimited columns [on hold]

I am just curious as to why big open source and commercial RDBMSs can't, don't or won't implement unlimited columns per table? Is there a technical or business reason why this can't be done. MongoDB ...
1
vote
0answers
29 views

ORA-00937 when calculating a sub-value in an aggregate select statement

The problem described below applies to Oracle 11g databases. I also tested the statements on MySQL and PostgreSQL with no problems of the kind mentioned in this question. I want to use an ...
0
votes
1answer
48 views

sql or hql query to find all parents of a particular record

I need a sql or hql query to find all parents of a particular record, that should work in oracle as well as mysql, for eg if I have the id: 201, the parents would be: 188, 187, 1. any help would ...
1
vote
0answers
41 views

Database Migration with Liquibase using different DBMS

Our customer is using Oracle and we want to use MySQL for development. Therefore our MySQL Scheme has to be in sync with Oracle. I tried to use Liquibase, but I get problems at the time of applying a ...
2
votes
1answer
66 views

Is data warehouse monitoring same as database monitoring? [closed]

I have a requirement, where data warehouse population is to be monitored. I am in confusion, and needed a clear picture. Is data warehouse different than database? eg. For monitoring database we ...
1
vote
1answer
53 views

Not able to update MySQL table using Oracle: Unknown column in 'where clause' {42S22,NativeErr = 1054}

I have the following tables: MySQL table: jti_member_interact CREATE TABLE `jti_member_interact` ( `INT_MEMBER_ID` int(11) NOT NULL, `INT_ID` int(11) NOT NULL AUTO_INCREMENT, `INT_SOURCE` ...
0
votes
0answers
27 views

How to manage MySQL database with Oracle Fusion Middleware?

Is it possible to connect and manage a MySQL database with Oracle Fusion Middleware?
-2
votes
1answer
77 views

Can I install MySql and Oracle 10g both Databases in same machine? [closed]

I have MySql Installed in my windows 7 machine and PHP on IIS. Now i need Oracle 10g anyway.I'm having king of dilemma to install Oracle 10g. If i can do so please suggest necessary steps and ...
1
vote
1answer
106 views

How to export a MySQLtable with a longBLOB column to an Oracle database?

In MySQL I have a table: Select * from Dummy; Columns like below: id name salary binary_col 1 a 100 A.pdf 2 b 200 b.pdf 3 c 300 c.pdf 4 d 400 d.pdf 5 e 500 e.pdf ...
1
vote
3answers
412 views

What's the most efficient UUID column type

For storing a 128 bits UUID there are multiple storage options: a byte[16] column two bigint/long(64 bits) columns a CHAR(36) column - 32 hex digits + 4 dashes. a UUID database specific column, if ...
0
votes
0answers
42 views

Migrate from mysql to oracle

I'm trying to migrate a db from mysql to oracle, I'm trying to follow the videos from the official page of oracle: Here! But I have a doubt, when I'm trying to do the step of "translate" I don't have ...
-1
votes
2answers
589 views

How to dump data from Oracle to MySql

In my migration project, i need to dump the data from oracle to mysql. So is there any utility or way i can do this operation? The data dump file in the form of .dmp.
2
votes
2answers
214 views

Design of an application log database

We are generating logs like following example(this is a table no actual pipes): 2014-06-10 09:00:03.457 | Channel1 | Operation3 | Function15 | 15ms 2014-06-10 09:00:08.245 | Channel2 | Operation5 | ...
0
votes
1answer
124 views

Unable to migrate local database to RDS instance

I recently created an MySQL instance on Amazon RDS. Unfortunately, I'm not able to connect to the instance from the MySQL command line. I will brief you the details. 1) I want to move/migrate my ...
1
vote
3answers
98 views

Mysql to Oracle communication

I have a website running with php and mysql on Centos(Amazon instance). The newly brought ERP(to be integrated with existing system) uses Oracle as db(located on a separate Windows Server). The orders ...
2
votes
0answers
227 views

How can I connect to a network MySQL server using ODBC?

Somewhere on my company's network there's a (Oracle) MySQL server named FOO. I see FOO reference in SAS code written by my team's analysts, who use SAS's PROC SQL command to connect to it using ODBC. ...
1
vote
0answers
131 views

Oracle equivalent of mysqldump [closed]

Is there a program that would let me dump a table as a set of insert statements. I do not want to use data pump as that generates a binary file, requires DB privileges and has a learning curve. For ...
2
votes
0answers
83 views

How to distribute a given database between multiple DBMS on a LAN? [closed]

Given a Database D, i need to distribute it over different DBMS in a LAN. D will be split into tables, and each DBMS will store a given table. Here is a sketch of what i need to do : I also need to ...
0
votes
2answers
75 views

How to store a database table in multiple disks with assigned ratio?

I am going to deploy database tables to multiple disks. My database layout would be like following example: There are 3 tables (Customer, Order, Product) and 4 disks (disk_A, B, C, D). Customer: 5% ...
0
votes
0answers
63 views

Slow exporting SAP Data Services to MySQL (Oracle is faster)

We've a MySQL 5.1 server and we are trying to import data from SAP Data Services from another server. It works but it takes 3h! We tried to setup an Oracle XE server to test the same operation and it ...
0
votes
2answers
203 views

What are definer and invoker rights in database, Oracle and MysQL?

What are definer and invoker rights in database, Oracle and MysQL? I just don't get it
0
votes
2answers
343 views

Warning before issuing delete/update command in mysql/oracle , then executes

Is there any utility , function either in mysql /oracle that if i issue some delete/update command wrongly , a message must prompt at command_line* (if possible in ubuntu) asking whether "you sure to ...
1
vote
1answer
83 views

Mysql, sql server, oracle tables get too large [closed]

I hear a lot about things that, it is a lot cheaper to buy new harddisk than pay staff to come up with genius ideas how to save resources. But what I don't understand, is how these databases handle a ...
0
votes
1answer
111 views

retrieve data based on a condition

I have 2 tables, TA and TB: TA -------- id name 1 a 2 b 3 c 4 d 5 e 6 f TB -------- id p_id name 1 1 a 2 1 b 3 1 c 4 2 a 5 2 b 6 2 d I need : if ...
0
votes
0answers
29 views

Reliability of blobs in MySQL

I'm in the process of migrating an application working with Oracle to MySQL. That application stores data in the form of blobs, which can be pretty big. The Oracle production database is 60 Gb large ...
0
votes
2answers
125 views

Recommendation for RDBMS for large table [closed]

I have been asked for recommendation on the optimal RDBMS for a large amount of data. The largest table would contain 2TB of data. My own largest table is only 400GB (mysql, performs very well). The ...
0
votes
0answers
142 views

Efficient, up-to-date way to import an Oracle database into MySql

Here's the situation: I need to automatically merge data from an Oracle and a MySql server into a single, new MySql server. The merging will happen daily, and the resulting server will be hosted on a ...
-5
votes
0answers
61 views

Website is working very slowly [closed]

We have replication from Oracle to MySQL via Oracle Golden Gate. Yesterday because of some issues we have rebuilt the replication from Oracle to MySQL (this is called opal replication). Now our ...
0
votes
1answer
222 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 ...
8
votes
1answer
937 views

Is there an execution difference between a JOIN condition and a WHERE condition?

Is there a performance difference between these two example queries? Query 1: select count(*) from table1 a join table2 b on b.key_col=a.key_col where b.tag = 'Y' Query 2; select ...
3
votes
2answers
1k views

A database in MySQL is a schema in Oracle : I do not understand this statement

Please help me understand this statement: A database in MySQL is a schema in Oracle. I have just started to use Oracle and I find it different from other RDBMS softwares I have used like MSSQL, ...
1
vote
0answers
714 views

Migrating from Oracle to MySQL using WorkBench Migration Tool

I am currently migrating from Oracle to MySQL and I am going to use the migration tool in workbench to help me with the procedure. I have entered my source connection details as follows: Database ...
1
vote
1answer
297 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 ...
2
votes
1answer
922 views

Database Link from Oracle 10g on Windows over to MySQL database

Didn't see any answers on this subject so hoping for a miracle! :-) I've got an Oracle 10g database running on Windows Server 2003 and I'd like to create a database link to an external MySQL database ...
4
votes
1answer
155 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
658 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 ...
8
votes
2answers
4k 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 ...
1
vote
1answer
1k views

Replicating data from Oracle to MySQL

I work with a vendor that does data analytics, and they currently receive a replication stream from some of our databases using a product called Goldengate (which is very expensive). Goldengate has ...
-1
votes
0answers
368 views

Synchronising SQL tables in two locations [closed]

We have a bit of a conundrum at the moment. ANSI SQL solutions please. We have two databases located at two different geographic locations and will be using the web for all traffic between the two ...
1
vote
1answer
198 views

What logical structure is used for storing rows in Oracle?

From the logical data separation point, there are tablespaces that consist of segments that consist of extend that consist of oracle blocks that consist of OS blocks. What logical structure actually ...
2
votes
2answers
365 views

simulate sequence on mysql in preparation for move to oracle

I've been developing an application against MySQL while a new development server has been slowly being set up. The new dev server will use oracle, and since we're getting close to it being ready, I ...
-8
votes
1answer
279 views

What are the edges of typical (or specific) paid databases like oracle of mysql compared to the free oness? [closed]

Note: I am building a startup. I am currently using mysql. I am pretty much stuck. Others recommend other free databases like mongodb. I am seriously considering paid one IF and only IF it gets better ...
10
votes
1answer
439 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 ...
-1
votes
1answer
78 views

Index Proposals

As a theoretical database question, if you are asked 'which indexes would you propose and why?' are the answers from primary, clustering and secondary index? How would we know if we should introduce ...
-1
votes
1answer
318 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. ...
0
votes
2answers
689 views

Commercial database systems versus open source database systems [closed]

Can anyone tell me what are the reasons for buying a commercial database system and not using an open-source free version? The reason for my question is that: Commercial systems cost upwards of ...
-1
votes
2answers
1k views

Data Base Administration Oracle vs MySql? [closed]

I have worked with MSSQL for a while now, but now we want to try to move to some open source for a specific part of the company's products or explore Oracle if possible. What would you say are the ...
2
votes
3answers
859 views

Move Oracle data to and from MySQL with the help of PHP?

My application is in PHP which by default uses MySQL db. I have connected MySQL & Oracle dbs with PHP. Now I want to move data from Oracle db into Mysql db through PHP. Is it possible to do? Is ...
6
votes
2answers
1k 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 ...
9
votes
3answers
5k views

Where can I find example databases for MySQL, SQL Server and Oracle?

I want to experiment with the 3 large database management systems. For this purpose it would be cool to have the same database (the same tables, etc.) for each of those. Where can I find sql scripts ...