...
- Parallelization-Type: (mandatory) Inter-Operator or Intra-Operator. If Inter-Operator type is selected, the given query plan is modified. If Intra-Operator type is selected, different physical operators are used, that provides multithreading (in Development).
- Parallelization degree: (mandatory) Defines the degree of parallelization that should be used. It is also possible to use the constant AUTO, to detect the available cores and use this value.
- Buffer-size: (optional) Defines the number of elements inside of the used buffers. There is also the possibility to use the constant AUTO, to use an default value.
...
- Optimization: (optional) With this parameter it is possible to enable or disable post optimization. Post optimization is done if two or more transformations are processed and it is possible to combine these transformations. Removes unneeded union and fragmentations. The optimization is only possible if fragment-operators have the same number of fragments and if the attributes are equal (only hashfragment). In addition to this it is not possible that there are stateful operators like unions or operators with stateful functions between both transformations. It is also not possible that there are splits of the datastream between both of them.
The following example shows the usage of this keyword. This example uses the inter-operator parallelization with an degree of 4 and an automatic buffersize.
| Code Block |
|---|
#PARSER PQL
#PARALLELIZATION INTER_OPERATOR 4 AUTO true
/// other possible definition of parameters for this keyword
#PARALLELIZATION (type=INTER_OPERATOR) (degree=4) (buffersize=AUTO) (optimization=true)
#RUNQUERY
windowBid = TIMEWINDOW({SIZE = [1, 'MINUTES'],
advance = [1, 'SECONDS']
}, bid)
windowAuction = TIMEWINDOW({SIZE = [10, 'MINUTES'],
advance = [1, 'SECONDS']
}, auction)
join = JOIN({PREDICATE = 'bid.bidder == auction.id'}, windowBid, windowAuction) |
...