Description:
Set primary key for a table sequence or an in-memory table and create index for the table at the same time.
Syntax:
T.keys@i(Ki,…;n)
Note:
The function sets primary key Ki,... for table sequence/in-memory table T and, in the meantime, creates an index over the key. Create hash index when the function only works with @i option.
Parameter:
|
Ki |
Primary key, which can be one or multiple; delete all keys of T when this parameter is absent |
|
T |
A table sequence/in-memory table |
|
n |
An integer greater than 1, which is length of the hash table; its default length is the table length; cannot create a serial byte index when this parameter is present |
Option:
|
@s |
Create a serial byte index for a serial byte primary key; omit parameter n when using this option |
|
@m |
Enable parallel processing to create the index |
|
@t |
Set the last Ki parameter as the time key and create index on it |
|
@n |
Create an sequence number key |
Return value:
A table sequence/in-memory table
Example:
Set key for a table sequence and create hash index:
|
|
A |
|
|
1 |
=demo.query("select EID,NAME,DEPT,SALARY from EMPLOYEE") |
|
|
2 |
=A1.keys@i(EID,DEPT;5) |
Set EID and DEPT as the key of A1’s table sequence and create a hash index whose size is 5. |
|
3 |
=A1.keys@im(EID,NAME) |
Create index using parallel processing. |
Set key for an in-memory table and create hash index:
|
|
A |
|
|
1 |
=demo.cursor("select EID,NAME,DEPT,SALARY,HIREDATE from EMPLOYEE").memory() |
|
|
2 |
=A1.keys@i(EID,DEPT;5) |
Set EID and DEPT as the key of A1’s in-memory table and create a hash index whose size is 5. |
|
3 |
=A1.keys@im(EID,NAME) |
Create index using parallel processing. |
Create indexes of others types:
|
|
A |
|
|
1 |
=demo.query("select EID,NAME,DEPT,SALARY,HIREDATE from EMPLOYEE") |
|
|
2 |
=A1.keys@in(EID) |
Set EID as the key of A1’s table sequence and create an sequence number index. |
|
3 |
=A1.keys@it(EID,HIREDATE) |
Set EID as basic key and HIREDATE as time key for A1’s table sequence, and create index on the time key. |
|
4 |
=A1.keys() |
Delete all keys of A1’s table sequence as parameters are absent. |
|
5 |
=A1.derive(k(EID:3):PID) |
Add a serial byte field to the table sequence. |
|
6 |
=A5.keys@is(PID) |
Set PID as the key of A5’s table sequence and create a serial byte index. |