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Description

Parameter

Example

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PQL
Code Block
themeEclipse
languagejavascript
titleJoin Operator
linenumberstrue
output = join({predicate = RelationalPredicate('auction_id = auction')},

...

 left,

...

 right)
CQL
Code Block
themeEclipse
languagesql
titleMap Operator
linenumberstrue
SELECT * FROM left, right WHERE auction_id = auction

LEFTJOIN

Description

Parameter

...

  • expressions: A list of expressions to map multiple incoming attribute values to out-coming attributes

Example

PQL
Code Block
themeEclipse
languagejavascript
titleMap Operator
linenumberstrue
output = MAP({
              expressions = ['auction_id * 5','sqrt(auction_id)']
             }, input)
CQL
Code Block
themeEclipse
languagesql
titleMap Operator
linenumberstrue
SELECT auction_id * 5, sqrt(auction_id) FROM input

...

  • attributes: A list of attribute names to project on

Example

PQL
Code Block
themeEclipse
languagejavascript
titleProject Operator
linenumberstrue
output = PROJECT({
                  attributes = ['auction', 'bidder']
                 }, input)
CQL
Code Block
themeEclipse
languagesql
titleProject Operator
linenumberstrue
SELECT auction, bidder FROM input

...

  • aliases: The list new attribute names to use from now on. If the flag pairs is set, aliases will be interpreted as pairs of (old_name, new_name). See the examples below.
  • type: By default, each schema has the name of the source from which the data comes from (i.e. it is the name of the type that is processed by this operator). With this parameter the type (source) name can be changed. This is needed in the SASE operator. 
  • pairs: Optional boolean value that flags, if the given list of aliases should be interpreted as pairs of (old_name, new_name). Default value is false.

Example

PQL
Code Block
themeEclipse
languagejavascript
titleRename Operator
linenumberstrue
// Renames the first attribute to auction_id, the second to bidder_id and the last to another_id.
output = RENAME({
                  aliases = ['auction_id', 'bidder_id', 'another_id']
                 }, input)

// Due the set flag pairs, the rename operator renames the attribute auction_id to auction and bidder_id to bidder.
output = RENAME({
                 aliases = ['auction_id', 'auction', 'bidder_id', 'bidder'], 
                 pairs = 'true'
                }, input)

CQL
Code Block
themeEclipse
languagesql
titleRename Operator
linenumberstrue
SELECT auction_id AS auction, bidder_id AS bidder FROM input

...

  • predicate: The predicate to evaluate over each incoming tuple

Example

PQL
Code Block
themeEclipse
languagejavascript
titleSelect Operator
linenumberstrue
output = SELECT({ 
                 predicate=RelationalPredicate('price > 100') 
                }, input)
CQL
Code Block
themeEclipse
languagesql
titleSelect Operator
linenumberstrue
SELECT * FROM input WHERE price > 100

...

  • wrapper: In Odysseus the default wrappers are GenericPush and GenericPull
  • transport: The transport defines the transport protocol to use.
  • protocol: The protocol parameter defines the application protocol to transform the processing results.
  • datahandler: This parameter defines the transform of the single attributes of the processing results.
  • options: Transport protocol and application protocol depending options

Example

PQL
Code Block
themeEclipse
languagejavascript
titleSender Operator
linenumberstrue
output = SENDER({sink='Sink',
                 wrapper='GenericPush',
                 transport='TCPClient',
                 protocol='CSV',
                 dataHandler='Tuple',
                 options=[['host', 'example.com'],['port', '8081'],['read', '10240'],['write', '10240']]
                }, input)
CQL
Code Block
themeEclipse
languagesql
titleSender Operator
linenumberstrue
CREATE SINK sink (timestamp STARTTIMESTAMP, auction INTEGER, bidder INTEGER, datetime LONG, price DOUBLE)
    WRAPPER 'GenericPush'
    PROTOCOL 'CSV'
    TRANSPORT 'TCPClient'
    DATAHANDLER 'Tuple'
    OPTIONS ( 'host' 'example.com', 'port' '8081', 'read', '10240', 'write', '10240' )

STREAM TO sink SELECT * FROM input 

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This operator calculates the union of two input sets

Parameter

none

Example

PQL
Code Block
themeEclipse
languagejavascript
titleUnion Operator
output = UNION(left, right)
CQL
Code Block
themeEclipse
languagesql
titleUnion Operator
linenumberstrue
SELECT * FROM left UNION SELECT * FROM rigtht

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