This worklog has been replaced with mariadb.org/jira

This site is here for historical purposes only. Do not add or edit tasks here!

 
 
 

WorkLog Frontpage Log in / Register
High-Level Description | Task Dependencies | High-Level Specification | Low-Level Design | File Attachments | User Comments | Time Estimates | Funding and Votes | Progress Reports

 Implement Block Nested Loop Hash Join
Title
Task ID128
Queue
Version
Status
Priority
Copies toIgor
Mneptok
Monty
Psergey
Sanja
Sergei
Timour

Created byIgor04 Aug 2010Done
Supervisor   
Lead Architect    
Architecture Review  
Implementor  
Code Review  
QA  
Documentation  
 High-Level Description
Block Nested Loop Hash (BNLH) Join Algorithm (also known as Classic Hash Join
Algorithm) can be applied when the join condition contains conjunctive equality
predicates over some attributes of the joined tables.
The algorithm employs the same logical schema as Block Nested Loop Join Algorithm.
A portions of rows of the left join operand fit into a preallocated join buffer
are put into the buffer. A hash table over the equi-join attributes for the rows
in the buffer is built. Then the table of the second operand is scanned and for
each row from this table the  matching rows in the join buffer are found using
the built hash table. These actions are repeated until there is no more rows can
be supplied by the first operand.
The algorithm requires as many scans of the second table as many times the join
buffer is refilled.
 Task Dependencies
Others waiting for Task 128Task 128 is waiting forGraph
 
 High-Level Specification
 Low-Level Design
 File Attachments
 NameTypeSizeByDate
 User Comments
 Time Estimates
NameHours WorkedLast Updated
Total0 
 Hrs WorkedProgressCurrentOriginal
Total000
 
 Funding and Votes
Votes: 0: 0%
 Make vote: Useless    Nice to have    Important    Very important    

Funding: 0 offers, total 0 Euro
 Progress Reports
(Psergey - Sat, 09 Oct 2010, 10:57
    
SergeyP started reviewing the code for this WL.

(Psergey - Sat, 09 Oct 2010, 10:56
    
Code Review updated:  -> Psergey


Report Generator:
 
Saved Reports:

WorkLog v4.0.0
  © 2010  Sergei Golubchik and Monty Program AB
  © 2004  Andrew Sweger <yDNA@perlocity.org> and Addnorya
  © 2003  Matt Wagner <matt@mysql.com> and MySQL AB