cachedTable

Syntax

cachedTable(updateFunc, retentionSeconds)

Arguments

updateFunc is a function without parameters. It must return a table.

retentionSeconds is a positive integer indicating the frequency (in seconds) to update the cached table.

Details

Create a special type of in-memory table: cached table. When querying the cached table, if the length of time since the last update exceeds a specified value,

updateFunc is executed automatically to update the cached table.

Examples

$ def f1(mutable t){
$     update t set id=id+1
$     return t
$ }
$ t=table(1..5 as id, 15 25 35 45 55 as val)
$ ct=cachedTable(f1{t}, 2);

$ select * from ct;

id

val

2

15

3

25

4

35

5

45

6

55

$ sleep(2100)
$ select * from ct

id

val

3

15

4

25

5

35

6

45

7

55

$ ct=NULL;