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0answers
256 views

How to Investigate the difference between query execution times?

I have a simple query, when executed directly in SQL Developer Studio (It's an Oracle Database) takes around 4 seconds. But when executed via my Java code it takes around 20 seconds. I'm using ...
1
vote
1answer
156 views

All images on a single table. Is a good idea?

I'm making the tables for an application, and I need many tables with images. Instead of storing the BLOBS on each table, I'm thinking on storing all the images (BLOB) on a single table, to unify the ...
0
votes
2answers
47 views

what is a better approach in replicating data from table to another? triggers or a third party ETL tool?

We have multiple tables which we need to retrieve data from and dump to one centralized table. Currently what we are doing is running an ETL job made from Pentaho, retrieve the records from the source ...
2
votes
3answers
1k views

Database view performance - good practice?

Often times at work we opt to create views in the database to expose the data that we want to work with instead of building some monster query in our code. Being somewhat new to this field my ...
0
votes
1answer
2k views

What happens if computer crashes after giving commit command

If we are updating a field in SQL and ALTER the row also. After giving the COMMIT command, the system is crashed. What will happen to the commands given, whether it will UPDATE and ALTER the table ...
1
vote
3answers
713 views

Select custom output formats from database with SQL

I am planning to make a simple rest service application, and I am currently deciding the architecture. I have decided that I want to write the middle layer in multiple languages, so that it is easy to ...
11
votes
2answers
7k views

In what order are rows fetched absent ORDER BY clause?

One programmer is testing and comparing the same application which uses the same database structure, and the same data, only in two separate databases, one with Oracle 8 and one with Oracle 9. The ...
0
votes
1answer
508 views

For PL/SQL, do large companies prefer ANSI SQL joins or old Oracle joins? [closed]

I am interviewing for a PL/SQL position with a large corporation. I will have to write a multiple choice exam. I am wondering whether the exam will likely use old-style joins (joining happens in the '...
5
votes
5answers
1k views

Alternatives for comparing data from different databases

I have two huge tables on separate databases. One of them has the information of all the SMS that passed through the company's servers while the other one has the information of the actual billing of ...
0
votes
1answer
9k views

how to compare two large sets of data using PL/SQL?

I have two different tables in two separate databases with around 1.5 million records each. (BTW: im working on oracle databases) The objective is to check if every record present in table A is ...
4
votes
3answers
633 views

two approaches to database modeling - which one to use when

recently I have noticed a new approach to data modeling vs what I have used so far. This seems to be a way to address modeling of an entity that has a very large set of fields and quite often many of ...
5
votes
2answers
171 views

What is the equivalent of functions and methods in SQL?

In language like C or Java, there are things like functions/methods to modularize and abstract stuff. What is there in SQL, specifically for Oracle? I've seen people talking about using views to ...