Package io.github.flink.gcp.connector.bigtable.table

Class BigtableTableSchema

java.lang.Object

io.github.flink.gcp.connector.bigtable.table.BigtableTableSchema

@Internal
public final class BigtableTableSchema
extends Object

The DDL schema of a bigtable table: which column is the row key, and which column family and qualifier every other column addresses.

The model is the HBase connector's, so that a table definition moves between the two with its schema intact:

Abbreviated, not compiled: deployment-specific connector options are omitted.

 CREATE TABLE bt (
   rowkey STRING,
   cf1 ROW<qual1 STRING, qual2 BIGINT>,
   cf2 ROW<metric DOUBLE>,
   PRIMARY KEY (rowkey) NOT ENFORCED
 ) WITH ('connector' = 'bigtable', ...)
 

Exactly one column is neither a ROW nor a MAP, and that column is the row key; every ROW column is a column family whose nested field names are the qualifiers. Upstream google/flink-connector-gcp's alternative — a value.format per family — was weighed and declined on #34: it cannot give a single qualifier its own type, and it ties a family to a format.

A MAP<STRING, V> or MAP<BYTES, V> column is a column family too, declared without its qualifiers: each entry is one qualifier and its latest cell, every value has the one type V, and the family is read and written whole. This is how GoogleSQL for Bigtable presents a family, and it is the form a schema derived from table metadata alone can take, since Bigtable stores families but neither qualifiers nor cell types (ADR-0172). The HBase connector has no such form, so a DDL using one does not move to it.

Column order is preserved, because it is what a projection's indexes refer to.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	BigtableTableSchema.Family	One column family: a ROW column whose nested fields are its qualifiers, or a MAP column whose entries are.
static final class	BigtableTableSchema.Qualifier	One qualifier: a nested field of a column family's ROW.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
List<BigtableTableSchema.Family>	getFamilies()	Returns the column families, in DDL order.
int	getFieldCount()	Returns the physical row's field count: its row key and its column families.
int	getRowKeyIndex()	Returns the position of the row-key column in the physical row.
String	getRowKeyName()	Returns the name of the row-key column.
org.apache.flink.table.types.logical.LogicalType	getRowKeyType()	Returns the declared type of the row-key column.
int	hashCode()
static BigtableTableSchema	of(org.apache.flink.table.types.logical.RowType rowType)	Reads the model out of a table's physical row type.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Method Details

of

public static BigtableTableSchema of(org.apache.flink.table.types.logical.RowType rowType)

Reads the model out of a table's physical row type.

Parameters:

rowType - the physical columns, in DDL order

Returns:

the parsed schema

Throws:

org.apache.flink.table.api.ValidationException - if the columns do not describe one row key and zero or more column families, or if a column's type, or a map's key or value type, has no cell encoding

getRowKeyIndex

public int getRowKeyIndex()

Returns the position of the row-key column in the physical row.

getRowKeyName

public String getRowKeyName()

Returns the name of the row-key column.

getRowKeyType

public org.apache.flink.table.types.logical.LogicalType getRowKeyType()

Returns the declared type of the row-key column.

getFamilies

public List<BigtableTableSchema.Family> getFamilies()

Returns the column families, in DDL order.

getFieldCount

public int getFieldCount()

Returns the physical row's field count: its row key and its column families.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object