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From dyozie <...@git.apache.org>
Subject [GitHub] incubator-hawq-docs pull request #60: HAWQ-1151 - add ambari procedures
Date Tue, 15 Nov 2016 00:17:15 GMT
Github user dyozie commented on a diff in the pull request:

    https://github.com/apache/incubator-hawq-docs/pull/60#discussion_r87922594
  
    --- Diff: ddl/ddl-table.html.md.erb ---
    @@ -132,7 +132,7 @@ Policies for different application scenarios can be specified to optimize
perfor
     
     Adjusting the values of the configuration parameters `default_hash_table_bucket_number`
and `hawq_rm_nvseg_perquery_limit` can tune performance by controlling the number of virtual
segments being used. In most circumstances, HAWQ's elastic runtime will dynamically allocate
virtual segments to optimize performance, so further tuning should not be needed..
     
    -Hash tables are created using the value specified in `default_hash_table_bucket_number`.
Explicitly setting this value can be useful in managing resources, as queries for hash tables
use a fixed number of buckets, regardless of the amount of data present. If a larger or smaller
number of hash buckets are desired, set this value before you CREATE TABLE. Resources are
dynamically allocated to a multiple of the number of nodes. If setting the value of `default_hash_table_bucket_number`
with hawq init --bucket\_number, the value should not exceed the value of `hawq_rm_nvseg_perquery_limit`,
which defines the maximum number of virtual segments that can be used for a query \(default
= 512, with a maximum of 65535\). Modifying the value to greater than 1000 segments is not
recommended.
    +Hash tables are created using the value specified in `default_hash_table_bucket_number`.
Explicitly setting this value can be useful in managing resources, as queries for hash tables
use a fixed number of buckets, regardless of the amount of data present. If a larger or smaller
number of hash buckets are desired, set this value before you CREATE TABLE. Resources are
dynamically allocated to a multiple of the number of nodes. If using `hawq init --bucket_number`
to set the value of `default_hash_table_bucket_number` during cluster initialization or expansion,
the value should not exceed the value of `hawq_rm_nvseg_perquery_limit`, which defines the
maximum number of virtual segments that can be used for a query \(default = 512, with a maximum
of 65535\). Modifying the value to greater than 1000 segments is not recommended.
    --- End diff --
    
    change "CREATE TABLE" to "create tables"  Also might want to tackle some of the passive
voice in this paragraph.


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