Read and generate parquet array column.
When D=1, R=0, representing an empty array. Empty array is not a null value, so the NullMap for this row is false,
the offset for this row is [offset_start, offset_end) whose `offset_start == offset_end`,
and offset_end is the start offset of the next row, so there is no value in the nested primitive column.
When D=0, R=0, representing a null array, and the NullMap for this row is true.
Parse parquet data with dictionary encoding.
Using the PLAIN_DICTIONARY enum value is deprecated in the Parquet 2.0 specification.
Prefer using RLE_DICTIONARY in a data page and PLAIN in a dictionary page for Parquet 2.0+ files.
refer: https://github.com/apache/parquet-format/blob/master/Encodings.md
1. Spark can set the timestamp precision by the following configuration:
spark.sql.parquet.outputTimestampType = INT96(NANOS), TIMESTAMP_MICROS, TIMESTAMP_MILLIS
DATETIME V1 only keeps the second precision, DATETIME V2 keeps the microsecond precision.
2. If using DECIMAL V2, the BE saves the value as decimal128, and keeps the precision of decimal as (precision=27, scale=9). DECIMAL V3 can maintain the right precision of decimal
# Proposed changes
Read and decode parquet physical type.
1. The encoding type of boolean is bit-packing, this PR introduces the implementation of bit-packing from Impala
2. Create a parquet including all the primitive types supported by hive
## Remaining Problems
1. At present, only physical types are decoded, and there is no corresponding and conversion methods with doris logical.
2. No parsing and processing Decimal type / Timestamp / Date.
3. Int_8 / Int_16 is stored as Int_32. How to resolve these types.
Analyze schema elements in parquet FileMetaData, and generate the hierarchy of nested fields.
For exmpale:
1. primitive type
```
// thrift:
optional int32 <column-name>;
// sql definition:
<column-name> int32;
```
2. nested type
```
// thrift:
optional group <column-name> (LIST) {
repeated group bag {
optional group array_element (LIST) {
repeated group bag {
optional int32 array_element
}
}
}
}
// sql definition:
<column-name> array<array<int32>>
```
