Neoview Query Guide (R2.3, R2.4, R2.5)

The PACK operator has one child. The description field for this operator contains:
Data TypeToken DescriptionToken
integerA sequential number assigned to the fragment. 0 is always master
executor and 1 is reserved for the Explain plan. Numbers 2 to n will
be ESP or DAM fragments.
fragment_id
integerThe fragment_id for the parent fragment of the current fragment.
Value is (none) for master executor.
parent_frag
textmaster, ESP, or DAMfragment_type
expr(text)Expression used to pack values of a row into a packed rowpack_expr
SAMPLE Operator
The SAMPLE operator occurs as a result of a sample clause in a query.
The SAMPLE operator has one child operator. The description field for this operator contains:
Data TypeToken DescriptionToken
integerA sequential number assigned to the fragment. 0 is always master
executor and 1 is reserved for the Explain plan. Numbers 2 to n
will be ESP or DAM fragments.
fragment_id
integerThe fragment_id for the parent fragment of the current fragment.
Value is (none) for master executor.
parent_frag
textmaster, ESP, or DAMfragment_type
expr(text)List of column references representing the outputs of the sample
operator. Indicates that the column has been sampled.
sampled_columns
expr(text)Expression representing the sampling expression. A simple random
selection, but could be more complex if the sample clause contains
a balance clause.
balance_expression
textIndication of the type of sampling being performed. Possible values
are RANDOM, PERIODIC, FIRST, and CLUSTER.
sample_type
expr(text)Specified order keys for a sample operation.required_order
UNPACK Operator
Use the UNPACK operator in a query plan when an array is used as input in a query (for example,
inserting rows from rowset arrays). The UNPACK operator extracts the elements from the array
to use in the query.
The UNPACK operator has one child. The description field for this operator contains:
Data TypeToken DescriptionToken
integerA sequential number assigned to the fragment. 0 is always master
executor and 1 is reserved for the Explain plan. Numbers 2 to n
will be ESP or DAM fragments.
fragment_id
integerThe fragment_id for the parent fragment of the current fragment.
Value is (none) for master executor.
parent_frag
textmaster, ESP, or DAMfragment_type
expr(text)Expression used to extract values from a packed rowunpack_expression
integerSystem-generated index used when accessing a packed rowindex_value
expr(text)The number of logical rows in the packed rowpacking_factor
54 Query Plan Operators