Sandro Fiore ([email protected]) Alessandro Negro ([email protected])
description
Transcript of Sandro Fiore ([email protected]) Alessandro Negro ([email protected])
Sandro Fiore ([email protected])Alessandro Negro ([email protected])
SPACI Consortium & University of Salento, Lecce
The Grid Relational Catalog ProjectTutorial
2GRelC Project - http://grelc.unile.it
What we will see during the tutorial
• Authorization
• Select Queries
‣ grelc-das-query-memory
‣ grelc-das-query-dime
‣ grelc-das-query-stream
• GRelC Portal
• https://grid.ct.infn.it/twiki/bin/view/GILDA/GRelCDataAccessService
• https://grid.ct.infn.it/twiki/bin/view/GILDA/GRelCPortal
• https://grid.ct.infn.it/twiki/bin/view/GILDA/GRelCPortalAdvanced
3GRelC Project - http://grelc.unile.it
Authorization framework
• Before starting be sure you have a valid proxy …
• To create a valid proxy, run the following command
‣ grid-proxy-init
• With this proxy you will be able to access the sakila database on grelc02.unile.it (only select statements)
4GRelC Project - http://grelc.unile.it
Select Queries
• To carry out SELECT queries you can use the following commands
‣ grelc-das-query-memory
‣ grelc-das-query-dime
‣ grelc-das-query-stream
• These kinds of query were designed to address high performance
5GRelC Project - http://grelc.unile.it
Single Query Memory
1. Display help
> grelc-das-query-memory -h
USAGE: query-das-memory [options]
-s, --server VAL Sets GRelC DAS IP or hostname (default: localhost)
-p, --port NUM Sets GRelC DAS port (default: 18500)
-D, --database VAL Sets grid database name
-Q, --query VAL Sets query value
-c, --chunk NUM Sets chunk dimension (default:0 no chunk)
-t, --table Prints result in table format (default)
-x, --xml Prints result in xml format
-H, --html Prints result in html format
-h, --help Shows usage
EXAMPLES:
query submission without chunking
grelc-das-query-memory -s hostname -p 18500 -D database -Q 'select * from table'
query submission with chunking
grelc-das-query-memory -s hostname -p 18500 -D database -Q 'select * from table' -c 50
6GRelC Project - http://grelc.unile.it
Single Query Memory
2. Submits a query and displays its result in tabular format. The result is transferred one-shot.
> grelc-das-query-memory -s grelc02.unile.it -p 18500 -D sakila -Q "select * from actor" -t
3. Submits a query and displays its result in XML format. The result is transferred one-shot.
> grelc-das-query-memory -s grelc02.unile.it -p 18500 -D sakila -Q "select * from actor" -x
4. Submits a query and displays its result in XML format. The result is transferred in chunks of 50 tuples. The result shown is exactly the same of example no. 3
> grelc-das-query-memory -s grelc02.unile.it -p 18500 -D sakila -Q "select * from actor" -x -c 50
7GRelC Project - http://grelc.unile.it
Single Query File
5. Display help
> grelc-das-query-dime -h
USAGE: query-das-dime [options]
-s, --server VAL Sets GRelC DAS IP or hostname (default: localhost)
-p, --port NUM Sets GRelC DAS port (default: 18500)
-D, --database VAL Sets grid database name
-Q, --query VAL Sets query value
-c, --chunk NUM Sets chunk dimension (default:0 no chunk)
-z, --gzip Compresses result file
-t, --table Prints result in table format (default)
-x, --xml Prints result in xml format
-h, --help Shows usage
EXAMPLES:
query submission with compression
grelc-das-query-dime -s hostname -p 18500 -D database -Q 'select * from table' -z
query submission with chunking
grelc-das-query-dime -s hostname -p 18500 -D database -Q 'select * from table' -c 50
8GRelC Project - http://grelc.unile.it
Single Query File
6. Submits a query and displays its result in tabular format. The result is transferred one-shot.
> grelc-das-query-dime -s grelc02.unile.it -p 18500 -D sakila -t -Q "select * from actor"
7. Submits a query and displays its result in XML format. The result is transferred one-shot.
> grelc-das-query-dime -s grelc02.unile.it -p 18500 -D sakila -x -Q "select * from actor"
8. Submits a query and displays its result in XML format. The result is transferred in chunks of 50 tuples.
> grelc-das-query-dime -s grelc02.unile.it -p 18500 -D sakila -x -Q "select * from actor" -c 50
9. Now, let's look at the files in your current folder. Each file is a resultset stored client-side.
> ls -lrta
9GRelC Project - http://grelc.unile.it
Single Query File
10. Let's see what's inside one of the resultsets stored client-side.
> more .grelc02.unile.it_18500_171-singlequery.xml
11. Submits a query and displays its result in XML format. The result is compressed (using -z option) and transferred in chunks of 50 tuples.
> grelc-das-query-dime -s grelc02.unile.it -p 18500 -D sakila -x -Q "select * from actor" -z
12. Now, let's look at the files in your current folder again. You can find a compressed and an uncompressed file for each resultset stored client-side.
> ls -lrta
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Single Query Stream
13. Submits a query and displays its result in tabular format. The result is transferred by using data streaming.
> grelc-das-query-stream -s grelc02.unile.it -p 18500 -D sakila -t -Q "select * from actor"
14. Submits a query and displays its result in XML format. The result is transferred one-shot.
grelc-das-query-stream -s grelc02.unile.it -p 18500 -D sakila -x -Q "select * from actor”
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GRelC Project - http://grelc.unile.it
GRelC Portal Authorization
• Before starting be sure you have a valid proxy with the correct GRelC DAS Role
• To create a valid proxy, run one of the following commands
• grid-proxy-init
• With this proxy you will be able to access the sakila database on grelc02.unile.it…
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Select your proxy
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Adding one entry to the GRelC DAS List
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Grid Databases Management
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Tables Management
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View Schema
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View Data
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Query Submission
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Query Submission
• Let’s start with a simple select query...
select * from film
• This query retrieves all of the films available in the “sakila” database
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Query Submission
• Let’s now retrieve a list of films whose length is longer than 90 minutes...
select * from film where length > 90
• Pretty cool! The GRelC Portal gives us a list of films
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Query Submission
• Why do not we search a list of actors involved in the films listed before?
select first_name, last_name, title, length from (film join film_actor on film.film_id=film_actor.film_id) join actor on actor.actor_id=film_actor.actor_id where length > 90
• 3 tables are now involved in our select query
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Query Submission
• What if we want to know the film category of the films listed before?
select category.name as category_name, first_name, last_name, title, length from (((film join film_actor on film.film_id=film_actor.film_id) join actor on actor.actor_id=film_actor.actor_id) join film_category on film.film_id = film_category.film_id) join category on category.category_id=film_category.category_id where length > 90
• 5 tables are now involved in our select query
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Query Submission
• Let us now know who sells the films listed before, together with the category and the actors.
select category.name as category_name, first_name, last_name, title, length from (((film join film_actor on film.film_id=film_actor.film_id) join actor on actor.actor_id=film_actor.actor_id) join film_category on film.film_id = film_category.film_id) join category on category.category_id=film_category.category_id where length > 90
• 8 tables are now involved in our select query
• You can enrich the query as you want, no matter how many tables are involved. If the DBMS understands your query, the GRelC DAS understands it too!