BOOLEAN and other built-in opaque data types

HCL OneDB™ also supports the BOOLEAN data type, which is a built-in opaque data type that can store true, false, or NULL values. The symbol t represents a literal BOOLEAN true value, and f represents a literal BOOLEAN false value.

BOOLEAN, BSON, JSON, and LVARCHAR are the only built-in opaque data types that can be returned by cross-server distributed queries or by other cross-server distributed DML operations. Column values of other built-in opaque data types cannot be retrieved by a distributed query (nor modified by INSERT, DELETE, MERGE, or UPDATE operations on a remote database) unless all of the tables that the DML operation accesses are in databases of the local HCL OneDB instance.

Similarly, in UDRs that perform distributed operations on databases of other HCL OneDB instances, BOOLEAN, BSON, JSON, and LVARCHAR are the only built-in opaque types that are valid as a parameter or as the returned data type of the UDR, which must be defined in all participating databases.

Besides the BOOLEAN type, other built-in opaque data types of HCL OneDB include BLOB, , BSON, JSON, CLOB, LVARCHAR, IFX_LO_SPEC, IFX_LO_STAT, INDEXKEYARRAY, POINTER, RTNPARAMTYPES, SELFUNCARGS, STAT, CLIENTBINVAL, and XID data types. These built-in opaque types are supported in the local database and in distributed operations across databases of the same server instance. The first five of these types are discussed in subsequent sections of this chapter.

HCL OneDB also supports the built-in opaque data types LOLIST, IMPEXP, IMPEXPBIN, and SENDRECV. These types cannot, however, be accessed in a remote database by DML operations, nor returned from a remote database by a UDR, because these data types do not have the required support functions. For more information about the data types that HCL OneDB supports in distributed transactions, see Data Types in Distributed Queries.