Projection Disk Space
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Projection Disk Space
Does the physical disk space taken up by projections count towards the licensed space utilization?
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- JimKnicely
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Re: Projection Disk Space
Vertica uses raw data size (as if it was exported in text format) to evaluate your license compliance. The physical space on disk is compressed data and is therefore typically smaller than the space used by raw uncompressed data.
Jim Knicely
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.
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Re: Projection Disk Space
Just to clarify, it's only data that counts against the license utilization, and not space taken up by a projection?
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- JimKnicely
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Re: Projection Disk Space
Not necessarily.
Vertica excludes the following when calculating the raw data size estimate:
Vertica excludes the following when calculating the raw data size estimate:
- 1. Multiple projections (underlying physical copies) of data from a logical database entity (table). Data appearing in multiple projections of the same table is counted only once.
2. Data stored in temporary tables.
3. Data accessible through external table definitions.
4. Data that has been deleted, but which remains in the database.
5. Data stored in the WOS.
6. Data stored in system and work tables such as monitoring tables, Data Collector tables, and Database Designer tables.
Jim Knicely
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.
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Re: Projection Disk Space
I found the exclusions on page 112 and just want further clarification.
For example, if I have a table such as:
And I create two projections such as:
Would this would mean that the space utilized by both projections will be counted towards the raw data size? If this is the case, the data of the table and projections are counted towards the raw data size, which is extremely costly.
For example, if I have a table such as:
Code: Select all
customer
-----------
A B C D
Code: Select all
CREATE PROJECTION customer_p1 AS
SELECT A, B
FROM customer
ORDER BY A
Code: Select all
CREATE PROJECTION customer_p2 AS
SELECT C, D
FROM customer
ORDER BY C
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- JimKnicely
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Re: Projection Disk Space
You are going to have a super projection on the table that includes all of the columns. Creating the additional projection won't count against your raw data usage.
Note, that's my understanding.
You can create a 100's of projections on the same table and their storage won't count against your license. But you'd have terrible DML performance
Code: Select all
dbadmin=> create table t (a int, b int, c int, d int);
CREATE TABLE
dbadmin=> create projection t_p1 as select a, b from t order by a;
WARNING 4116: No super projections created for table snowfall.t.
HINT: Default super projections will be automatically created with the next DML
CREATE PROJECTION
dbadmin=> create projection t_p2 as select c, d from t order by c;
WARNING 4116: No super projections created for table snowfall.t.
HINT: Default super projections will be automatically created with the next DML
CREATE PROJECTION
dbadmin=> insert into t values (1, 2, 3, 4);
OUTPUT
--------
1
(1 row)
dbadmin=> select projection_name, is_super_projection from projections where anchor_table_name = 't';
projection_name | is_super_projection
-----------------+---------------------
t_p1 | f
t_p2 | f
t_b0 | t <== Only the raw data from one of buddy projections is counted
t_b1 | t
(4 rows)
You can create a 100's of projections on the same table and their storage won't count against your license. But you'd have terrible DML performance
Jim Knicely
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.
Note: I work for Vertica. My views, opinions, and thoughts expressed here do not represent those of my employer.