'Extract, Transform and Load': Data load processing, normally in the context of data warehouse systems.

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19
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7answers
5k views

Any Open Source / free ETL out there?

I was using Pentaho Data Integration even before Pentaho bought it and call it that. I have the last free version. I went on their website recently to see if they had released another version only to ...
14
votes
3answers
6k views

What are the arguments in favor of using ELT process over ETL?

I realized that my company uses an ELT (extract-load-transform) process instead of using an ETL (extract-transform-load) process. What are the differences in the two approaches and in which situations ...
12
votes
3answers
11k views

How do I run a large script with many inserts without running out of memory?

Question: I have a script with around 45 thousand insert from select statements. When I try and run it, I get an error message stating that I have run out of memory. How can I get this script to run? ...
12
votes
3answers
7k views

Are regular VACUUM ANALYZE stil recommended under 9.1?

I'm using PostgreSQL 9.1 on Ubuntu. Are scheduled VACUUM ANALYZE still recommended, or is autovacuum enough to take care of all needs? If the answer is "it depends", then: I have a largish database ...
8
votes
4answers
782 views

Is there a standard language/interface for programmatic ETL in SQL Server?

I'm currently in the process of creating ETLs for our data warehouse. We're using SSIS 2008, but we're running into issues, the biggest of which is the difficulty in re-using components. We have ...
8
votes
2answers
5k views

PostgreSQL for high volume transactions and for Data warehousing

Am quite new to PostgreSQL, I have never done a large deployment using it before. But, I have good experience in enterprise solutions and I want to try and apply some of what I learned using ...
7
votes
3answers
100 views

Tablespace on ephemeral storage

For performance reasons in some scenarios, e.g. Amazon EC2, you have access to a faster and cheaper storage device, which loses all its data on reboots, so it is called "ephemeral". This question is ...
6
votes
5answers
330 views

SSIS ETL Question/Option

In our current prod environment, when the ETL launches, it first checks an environmental variable at the OS level which tells it where the "config" database and table is for it to get the necessary ...
6
votes
1answer
2k views

Duplicating some rows of a data flow in SSIS

I have a data flow to migrate data from an old database to a new one. The old design had all the data and historical information (changes) stored in a single table with a "version" (incrementing ...
5
votes
1answer
2k views

ETL: extracting from 200 tables - SSIS data flow or custom T-SQL?

Based on my analysis, a complete dimensional model for our data warehouse will require extraction from over 200 source tables. Some of these tables will be extracted as part of an incremental load and ...
4
votes
3answers
1k views

How can I make my SSIS process consume more resources and run faster?

I have a daily ETL process in SSIS that builds my warehouse so we can provide day-over-day reports. I have two servers - one for SSIS and the other for the SQL Server Database. The SSIS server ...
4
votes
1answer
307 views

Dodgy causes of ORA-12549?

I am dealing with a rather massive ETL processing which keeps throwing me the ORA-12549 error. Have been looking for problems in the database so far and nothing. The DBA says the database is "fine" - ...
4
votes
1answer
404 views

Methodology & Architecture to Create ETL Process

What book or webpage can I read the architecture and methodology for creating ETL process? In other words, I'm looking for "how to do it" to create a ETL process when you have many source system to ...
4
votes
4answers
895 views

best ETL design to transfer transaction tables records into the data-warehouse

I have 2 type of tables to populate the data-warehouse with every day, lookup tables or configuration tables with few 100s records, and thats easy where i just truncate and refill the table. but for ...
4
votes
4answers
1k views

What options exist for copying data between servers on a regular basis?

My apologies if this has already been answered. I've searched SO and of course here on DBA, and am surprised to find no close matches. Specifically, I'm looking for a solution which survives schema ...
4
votes
1answer
937 views

SQL 2008: agent job error in opening excel files using DTS package

I have a SQL 2008 server (SQL2008S1) with Excel installed on it. I had to migrate databases and DTS packages from a SQL 2000 server (SQL2000S2) to this server. 1 DTS package is trying to access an ...
4
votes
1answer
128 views

Is there a non-DDL way to preserve back-references when staging data into production?

Let's say I've got this hypothetical schema: Source (OLTP) DB: Table Orders ------------ OrderID int IDENTITY (PK), CustomerID int NOT NULL, OrderAmount decimal NOT NULL Destination (DSS) DB: ...
4
votes
1answer
225 views

Large difference in disk space used by partitions

I have a partitioned table that contains about 155 million records total. It's partitioned by year and the partitions for both the current and previous years contain about 25 million records each. ...
4
votes
1answer
194 views

Is there a standard way to replace codes with values from a lookup table for reporting or analytics?

Suppose I have a "main" table that was probably heavily normalized and consists largely of columns that merely contain codes that are lookups into other tables (they are probably foreign keys but feel ...
4
votes
2answers
454 views

What is the best practice for mapping from natural keys to integer-based keys? (ETL)

This question originates more from an "enterprise architecture" point of view. (Reason being, our company is just starting to get into data management, and actually having DBA's -- I know, horrific ...
4
votes
1answer
1k views

MySQL failing and very slow on importing a large file

I have a 47 GB MySQL dump of a single table: http://dumps.wikimedia.org/commonswiki/latest/commonswiki-latest-image.sql.gz I ultimately want it into PostgreSQL, but since I didn't figure out an easy ...
4
votes
1answer
3k views

Importing a large column (8000 chars) from Excel using SSIS

I'm trying to set up a regular import of an excel spreadsheet that we get from a vendor. I'm using SQL 2008 R2 SSIS to import it into a table. The problem connection manager is an OLE DB connection ...
3
votes
3answers
533 views

How can I use an ETL?

I know that those letters mean Extract, Transform, and Load. But, when I used it at first, I thought that during the Transform phase I could do plenty of different joins on data that I've extracted ...
3
votes
1answer
80 views

Replace column values?

I recently got into SSIS and haven't been able to find what I am trying to achieve anywhere on the web. I am trying to take some rows as input, and then replace one specific column's value with ...
3
votes
2answers
703 views

Is this a good strategy for importing a large amount of data and decomposing as an ETL?

I have a set of five tables (a highly decomposed schema for an ETL if I understand the nomenclature) that I'm going to load via bulk import, then run some inserts from those five tables into a SLEW of ...
3
votes
0answers
442 views

SSIS Recordset Destination error

I have an SSIS package targeted at SQL Server 2012. I have it deployed into the Stored Packages in Integration Services and then have a SQL Server Agent job which executes it. The first part of the ...
2
votes
4answers
4k views

Quick way to validate two tables against each other

We're doing an ETL process. When all is said and done there are a bunch of tables that should be identical. What is the quickest way to verify that those tables (on two different servers) are in ...
2
votes
3answers
3k views

Inserting rows into other table whilst preserving IDENTITY

I'm performing ETL logic on a SQL Server table. I'm going to be synchronizing data from one table to another. For all of the records that need to be added to the target table based on the source ...
2
votes
3answers
1k views

ETL: extraction strategy for 200 source databases

What is the best extraction strategy for approximately 200 SQL Server 2005 source databases (same schema) for a daily load into a staging area in preparation for data warehouse cleansing, ...
2
votes
3answers
1k views

Is it good idea to change Simple Recover Model into Bulk-Logged on ETL system?

We are having an ETL process which inserts lots of data into tables. This database is set to Simple Recovery Model and the transaction log is growing a lot. I was thinking that would it help to set ...
2
votes
1answer
788 views

Does surrogate key assignment for a fact table require that the source data has natural keys?

Let's say I have a simple OLTP database with orders, products, and customers: And from it, I am building a data mart with an orders fact table, product dimension, customer dimension, and date ...
2
votes
2answers
493 views

how to insert multiple columns(around 40) into my sql database using java

i have a program to read the content of an excel file to my-sql db. i have 40 columns in excel and i created a table of 40 fields. and i want to import the data from excel into corresponding table ...
2
votes
3answers
904 views

Loading a FACT table per day

I have a database with 13 billion rows, per day I have around 20-30 mio rows. On top of this I have one cube, one of its dimensions is DateTime that goes down to milliseconds. To load the fact table I ...
2
votes
1answer
761 views

What are the best practices for ETL of data from one OLTP system to another?

First off, I want to post that I am a developer and not a DBA, so I am trying to approach this from the standpoint of what is the best thing to do, rather than just assuming I can do everything ...
2
votes
4answers
231 views

SQL Server: Database integration and synchronization

I have n SQL Server databases with the same data schema. On the other hand i have a web application that needs to retrieve, for some entities, the union of the information stored into the n ...
2
votes
2answers
119 views

Best Practices for Testing Application Dashboard Data

We have a dashboard that contains metrics based on a 6 month reporting period. Users log in and see their metrics based on the current 6-month reporting period. Every 6 months, we load new metrics ...
2
votes
1answer
85 views

Data Extract and submit across the network

I've been given a somewhat vague requirement regarding a data extract process which I need some help with. I'm fairly new to database warehousing etc. but I will try to explain everything relevant. ...
2
votes
0answers
404 views

How to do automated archiving for a SQL Server database based on interpretation of database metadata?

I am looking for a solution giving me automated archiving of SQL Server databases based on a smart interpretation of table relationships that is able to archive records from related tables minimizing ...
1
vote
2answers
2k views

Advice for ETL from Oracle to SQL Server?

I'm building a data mart in SQL Server which needs to extract each month from an Oracle database. Currently this is done by exporting to flat files, then running all the inserts/updates in SQL ...
1
vote
2answers
1k views

Moving data from Oracle to SQL Server : Table size optimization

I am loading data using SSIS from Oracle to an SQL Server database. One table I moved had a size of 4 MB under Oracle but when loaded to SQL Server, the size grows to 7.96 MB! I analyzed the size ...
1
vote
2answers
191 views

What is a good solution for reliably transferring data between SQL Server and PostgreSQL?

In analyzing some of our business data, we're realizing that we need to join data across disparate data sources. For example, our application data is warehoused in Postgres (ported from MongoDB via ...
1
vote
1answer
88 views

Tips for catching changes in table data over time interval for export to Data Warehouse

I've recently been tasked with exporting data from one of our databases to a central Data Warehouse. The export is supposed to be incremental since a full load every 24 hours would be a massive waste ...
1
vote
2answers
4k views

Error on SELECT - Primary filegroup is full

A SQL Server 2008 R2 database view unions several transaction table. The query has been slow over the couple of months and the dev team is planning to recreate the query. I need to ETL the results ...
1
vote
1answer
106 views

Expanding contractions/number ranges into separate records [closed]

I am planning the migration of a directory of image files plus a FileMaker-database containing the corresponding metadata into an Imagic IMS database (formerly known as ImageAccess). The vendor ...
1
vote
1answer
110 views

Clustered Index with nightly ETL process

We have a nightly ETL process that involves data from many different sources being flattened, and loaded into a completely denormalized table on SQL Server 2008 for reporting. The clustered index on ...
1
vote
3answers
170 views

Looking for ideas on maintaining data warehouse in close to real-time - ETL tools, etc

I have done a fair number of traditional data warehouse implementations where the loads were done in a batch-oriented manner, i.e. the data is refreshed nightly or, at most, every few hours. I now ...
1
vote
1answer
1k views

Loading multiValued fields into Solr via flat file, and possibly value position preservation in those fields

A hobby web project of mine uses data from many sources, some flat, some highly normalized. My ETL process boils all sources down to one logical table (which is soon to include some multi-valued ...
1
vote
1answer
478 views

What are the best practices for ETL of data from one OLTP system to another, Part 2?

Ok, I originally started a question a ways back called "What are the best practices for ETL of data from one OLTP system to another?". And as you can probably tell from most of my questions so far, ...
1
vote
1answer
622 views

ActiveX script throwing runtime error inside DTS package

I am a DBA. We have migrated SQL 2000 databases + DTS packages to SQL 2008. One of the DTS packages runs an ActiveX script to open an Excel file (which has runs macros when you open it). Coding ...
1
vote
1answer
43 views

How to deal with multiple error columns in data flow

I'm writing a simple package to load data into tables and a I have multiple destinations within the same package. I'm attempting to first attempt batch inserts but want to fall back to row by row in ...