parquet-java Compat Filters

Filter predicates of the hardwood-parquet-java-compat module. For setting up a filtered read, see Parquet-Java Compatibility.

Predicates

FilterApi offers these predicates:

Kind	Methods	Columns
Comparison	eq, notEq	all six column types
Comparison	lt, ltEq, gt, gtEq	all but booleanColumn
Set	in, notIn	all six column types
Logical	and, or, not	any predicates

contains and userDefined are not available. in and notIn take a non-empty Set; an empty one throws IllegalArgumentException when the predicate is built.

Binary literals

A Binary literal, in a comparison or in a set, converts by the type of the column it filters:

Column	Literal
DECIMAL over BYTE_ARRAY or FIXED_LEN_BYTE_ARRAY	the big-endian two's-complement unscaled value at the column's scale, of any width; empty bytes are zero
FLOAT16, with a 2-byte literal	the IEEE half the two little-endian bytes encode
any other	the stored bytes

Nulls

A null literal throws IllegalArgumentException when the reader is built, whether it is the value of a comparison or an element of an in / notIn set. The shim has no null test; Hardwood's own reader API filters on nulls with isNull / isNotNull (see Query Controls).

A null row matches no comparison and no set predicate, so notEq and notIn return no null rows, where parquet-java's record filter returns them. Compatibility Philosophy explains this choice.