Hi Marc, Gang has already explained it. Logical type is an "annotation" on a primitive type. >From parquet-java code point of view, there is the PrimitiveTypeName to represent the primitive type, LogicalTypeAnnotation to represent the logical type and there is Type (and its extensions: PrimitiveType, GroupType, MessageType) to represent the whole together. You cannot convert a LogicalTypeAnnotation into a Type 1-to-1, because it has a lack of information. For example a DecimalLogicalTypeAnnotation(scale, precision) can be put on the primitive types INT32, INT64, BYTE_ARRAY, and FIXED_LEN_BYTE_ARRAY.
Cheers, Gabor marc nicole <mk1853...@gmail.com> ezt írta (időpont: 2025. márc. 29., Szo, 10:35): > @GangWu I think you are mistaken, since I can create a PrimitiveType (or a > GroupType) knowing the type of a LogicalTypeAnnotation (through > getString()). > > Please anyone to clarify this? > > Le mer. 26 mars 2025 à 04:26, marc nicole <mk1853...@gmail.com> a écrit : > > > I don't understand, it can also be a PrimitiveType. > > Btw if it is there's the following function to convert back a > > LogicalTypeAnnotation to a PrimitiveType and hence to Type > > > > withLogicalTypeAnnotation > > < > https://www.javadoc.io/static/org.apache.parquet/parquet-column/1.15.0/org/apache/parquet/schema/PrimitiveType.html#withLogicalTypeAnnotation-org.apache.parquet.schema.LogicalTypeAnnotation- > > > > (LogicalTypeAnnotation > > < > https://www.javadoc.io/static/org.apache.parquet/parquet-column/1.15.0/org/apache/parquet/schema/LogicalTypeAnnotation.html > > > > logicalType) > > > > Otherwise (GroupType) which constructor is most suitable for the > > conversion. > > > > Le mer. 26 mars 2025 à 04:18, Gang Wu <ust...@gmail.com> a écrit : > > > >> No, LogicalType is a part (or an attribute) of GroupType so you might > get > >> a > >> LogicalTypeAnnotation from a GroupType but not the opposite. > >> > >> On Wed, Mar 26, 2025 at 10:45 AM marc nicole <mk1853...@gmail.com> > wrote: > >> > >> > I have a LogicalTypeAnnotation.StringLogicalTypeAnnotation created > >> through > >> > stringType() ( > >> > > >> > > >> > https://www.javadoc.io/doc/org.apache.parquet/parquet-column/latest/org/apache/parquet/schema/LogicalTypeAnnotation.html > >> > ) > >> > ( > >> > > >> > > >> > https://www.javadoc.io/doc/org.apache.parquet/parquet-column/latest/org/apache/parquet/schema/LogicalTypeAnnotation.StringLogicalTypeAnnotation.html > >> > ) > >> > > >> > Is there a way to convert it to Type > >> > > >> > > >> > https://www.javadoc.io/doc/org.apache.parquet/parquet-column/latest/org/apache/parquet/schema/GroupType.html > >> > > >> > Thanks. > >> > > >> > > >
