Help Center/ GaussDB(DWS)/ Developer Guide/ Standard data warehouse (9.1.0.x)/ GaussDB(DWS) Development Design Proposal/ Detailed Design Rules for GaussDB(DWS) Objects/ Rules for Using Custom GaussDB(DWS) External Functions (pgSQL/Java)
Updated on 2024-12-18 GMT+08:00
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Rules for Using Custom GaussDB(DWS) External Functions (pgSQL/Java)

  • [Notice] Java UDFs can perform some Java logic calculation. Do not encapsulate services in Java UDFs.
  • [Notice] Do not connect to a database in any way (for example, by using JDBC) in Java functions.
  • [Notice] Only the data types listed in the following table can be used. User-defined types and complex data types (Java Array and derived classes) are not supported.
  • [Notice] User-defined aggregation functions (UDAFs) and user-defined table-generating functions (UDTFs) are not supported.
Table 1 PL/Java mapping for default data types

GaussDB(DWS)

Java

BOOLEAN

boolean

"char"

byte

bytea

byte[]

SMALLINT

short

INTEGER

int

BIGINT

long

FLOAT4

float

FLOAT8

double

CHAR

java.lang.String

VARCHAR

java.lang.String

TEXT

java.lang.String

name

java.lang.String

DATE

java.sql.Timestamp

TIME

java.sql.Time (stored value treated as local time)

TIMETZ

java.sql.Time

TIMESTAMP

java.sql.Timestamp

TIMESTAMPTZ

java.sql.Timestamp