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Questions tagged [redshift]

Redshift : Amazon's Column-Oriented Database Product

First released Feb 15, 2013, Redshift became part of the cloud within Amazon Web Services but is distinguished from Amazon RDS. It can handle JDBC/ODBC connections and allow accessing to a variety of BI Tools such as

  • Oracle BI Suite (Enterprise Edition)
  • Pentaho
  • MicroStrategy
  • Jaspersoft
  • and more

For more info, please read the following:

168 questions
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Grant SELECT on all tables in Redshift

I am trying to assign SELECT privilege to a group in Redshift. So I created a group and a user in that group: CREATE GROUP data_viewers; CREATE USER PASSWORD '' IN GROUP data_viewers; Now I would like to allow this group to be able…
Salvador Dali
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Redshift table not showing up in tables for schema?

On Redshift, why doesn't my table show up in the following query? It definitely exists, as shown by the next query I run. I want a way to list all tables for a schema: mydb=# select distinct(tablename) from pg_table_def where schemaname = 'db'; …
Some Guy
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How to increase column size in Redshift database tables?

In oracle, I can: Alter table table_name modify column_name datatype; Is this possible in a redshift database?
Vinoth _S
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Alternative to EAV for dynamic fields in a star schema data warehouse

I need to support dynamic fields and values in a big datawarehouse for storing API requests log, my user case is that I need to store all API requests query string and able to perform query against them in the future (so it is not just storage, so I…
Howard
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Dimensional Modeling and ETL in Redshift

I have been researching Amazon's Redshift database as a possible future replacement for our data warehouse. My experience has always been in using dimensional modeling and Ralph Kimball's methods, so it was a little weird to see that Redshift…
njkroes
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Storing multiple tags on analytics database

I would like to store user purchase custom tags on each transaction, example if user bought shoes then tags are "SPORTS", "NIKE", SHOES, COLOUR_BLACK, SIZE_12,.. These tags are that seller interested in querying back to understand the sales. My…
Kanagavelu Sugumar
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Simple queries to Redshift really slow

I just started testing AWS Redshift and populated a single node with the AWS sample data. Querying a table with 10 or ~400 rows takes around 2 seconds, uncached. I'm not sure if I'm misunderstanding something, but I assumed that would be a lot…
Till
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Deduplicate SELECT statements in relational division

I have a query that does a lot of duplicate work: SELECT visitor_id, '1'::text AS filter FROM events WHERE id IN (SELECT event_id FROM params WHERE key = 'utm_campaign' AND value = 'campaign_one') AND id IN (SELECT event_id…
Sam
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Is it possible to Clone a RedShift Database?

For some test and development work we would like the ability to routinely clone existing RedShift databases (all schema and all data). Something like a backup-restore. The best I can find starts by creating a snapshot of the entire cluster, which…
MatBailie
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Can't DROP GROUP, cannot be dropped because some objects depend on it

RDS Version: PostgreSQL 8.0.2 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.2 20041017 (Red Hat 3.4.2-6.fc3), Redshift 1.0.1161 I've been wrestling with this issue for a few days now, and all solutions I've found here and the AWS Forums aren't…
squeekwull
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Median absolute deviation for time series outlier detection in Amazon Redshift

Context I am tasked with trying to detect outliers in time series data in an Amazon Redshift (PostgreSQL) system. Also known as a public holiday detector around the office. The method I have been using takes a windowed average of the previous N data…
Josh Peak
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Understand why rank() over doesn't fit to don't select duplicates rows

I would like to understand why I have different results I have a table called active_transfert where I log image transfert user_id | image_id | created_at --------|----------|----------- 1 |1 |2014-07-10 1 |2 …
Mio
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Redshift: Return rows if value exists in cell array

How do I return the rows that include a particular value in a column's cell array? Imagine we have a table like so: id name phone values 1 Taylor xxx.xxx.xxxx [4,6,5] 2 John yyy.yyy.yyyy [1,5,2] 3 Peter …
Myg0t
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Drop user in redshift which has privilege on some object

I have a pretty standard problem that I can't resolve. I want to remove a user in redshift DROP USER u_A; which returns me: user "u_A" cannot be dropped because the user has a privilege on some object. The problem is that I have no idea what kind of…
Salvador Dali
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Storage size for varchar length in Redshift

So, a lot of databases will store the length prefix for a varchar field in 1 byte if the length is less than 255, and 2 bytes if it is more. For example, the MySQL docs say: In contrast to CHAR, VARCHAR values are stored as a 1-byte or 2-byte…
John Chrysostom
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