Joins: Difference between revisions
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(Created page with "== Problem Description== An SQL join clause - corresponding to a join operation in relational algebra - combines columns from one or more tables in a relational database. == Bounds Chart == 350px == Step Chart == 350px == Improvement Table == {| class="wikitable" style="text-align:center;" width="100%" !width="20%" | Complexity Classes !! width="40%" | Algorithm Paper Links !! width="40%" | Lower Bounds Pape...") |
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== | {{DISPLAYTITLE:Joins (Joins)}} | ||
== Description == | |||
An SQL join clause - corresponding to a join operation in relational algebra - combines columns from one or more tables in a relational database. | |||
== | == Parameters == | ||
$m,n$: sizes of input tables | |||
== Table of Algorithms == | |||
{| class="wikitable sortable" style="text-align:center;" width="100%" | |||
! Name !! Year !! Time !! Space !! Approximation Factor !! Model !! Reference | |||
|- | |- | ||
| | |||
| | | [[Nested loop join ( Joins)|Nested loop join]] || 1960 || $O(nm)$ || $O({1})$ || Exact || Deterministic || | ||
| | |||
|- | |- | ||
| | | [[Sort merge join ( Joins)|Sort merge join]] || 1960 || $O(nlogn + mlogm)$ || $O(n+m)$? || Exact || Deterministic || | ||
| | |||
| | |||
|- | |- | ||
| | | [[Hash join ( Joins)|Hash join]] || 1960 || $O(n+m)$ || $O(n+m)$? || Exact || Deterministic || | ||
| | |||
| | |||
|- | |- | ||
| | |} | ||
== Time Complexity Graph == | |||
[[File:Joins - Time.png|1000px]] | |||
Latest revision as of 09:07, 28 April 2023
Description
An SQL join clause - corresponding to a join operation in relational algebra - combines columns from one or more tables in a relational database.
Parameters
$m,n$: sizes of input tables
Table of Algorithms
| Name | Year | Time | Space | Approximation Factor | Model | Reference |
|---|---|---|---|---|---|---|
| Nested loop join | 1960 | $O(nm)$ | $O({1})$ | Exact | Deterministic | |
| Sort merge join | 1960 | $O(nlogn + mlogm)$ | $O(n+m)$? | Exact | Deterministic | |
| Hash join | 1960 | $O(n+m)$ | $O(n+m)$? | Exact | Deterministic |
Time Complexity Graph
