@Deprecated public class Fastpath extends Object
This class implements the Fastpath api.
This is a means of executing functions embedded in the backend from within a java application.
It is based around the file src/interfaces/libpq/fe-exec.c
Constructor and Description |
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Fastpath(BaseConnection conn)
Deprecated.
Initialises the fastpath system.
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Modifier and Type | Method and Description |
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void |
addFunction(String name,
int fnid)
Deprecated.
This adds a function to our lookup table.
|
void |
addFunctions(ResultSet rs)
Deprecated.
This takes a ResultSet containing two columns.
|
static FastpathArg |
createOIDArg(long oid)
Deprecated.
Creates a FastpathArg with an oid parameter.
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@Nullable Object |
fastpath(int fnId,
boolean resultType,
FastpathArg[] args)
Deprecated.
please use
fastpath(int, FastpathArg[]) |
byte[] |
fastpath(int fnId,
FastpathArg[] args)
Deprecated.
Send a function call to the PostgreSQL backend.
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@Nullable Object |
fastpath(String name,
boolean resulttype,
FastpathArg[] args)
Deprecated.
Use
getData(String, FastpathArg[]) if you expect a binary result, or one
of getInteger(String, FastpathArg[]) or
getLong(String, FastpathArg[]) if you expect a numeric one |
byte[] |
fastpath(String name,
FastpathArg[] args)
Deprecated.
Send a function call to the PostgreSQL backend by name.
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byte[] |
getData(String name,
FastpathArg[] args)
Deprecated.
This convenience method assumes that the return value is not an Integer.
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int |
getID(String name)
Deprecated.
This returns the function id associated by its name.
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int |
getInteger(String name,
FastpathArg[] args)
Deprecated.
This convenience method assumes that the return value is an integer.
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long |
getLong(String name,
FastpathArg[] args)
Deprecated.
This convenience method assumes that the return value is a long (bigint).
|
long |
getOID(String name,
FastpathArg[] args)
Deprecated.
This convenience method assumes that the return value is an oid.
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public Fastpath(BaseConnection conn)
conn
- BaseConnection to attach to@Deprecated public @Nullable Object fastpath(int fnId, boolean resultType, FastpathArg[] args) throws SQLException
fastpath(int, FastpathArg[])
fnId
- Function idresultType
- True if the result is a numeric (Integer or Long)args
- FastpathArguments to pass to fastpathSQLException
- if a database-access error occurs.public byte[] fastpath(int fnId, FastpathArg[] args) throws SQLException
fnId
- Function idargs
- FastpathArguments to pass to fastpathSQLException
- if a database-access error occurs.@Deprecated public @Nullable Object fastpath(String name, boolean resulttype, FastpathArg[] args) throws SQLException
getData(String, FastpathArg[])
if you expect a binary result, or one
of getInteger(String, FastpathArg[])
or
getLong(String, FastpathArg[])
if you expect a numeric onename
- Function nameresulttype
- True if the result is a numeric (Integer or Long)args
- FastpathArguments to pass to fastpathSQLException
- if something goes wrongfastpath(int, FastpathArg[])
,
fastpath(String, FastpathArg[])
public byte[] fastpath(String name, FastpathArg[] args) throws SQLException
Send a function call to the PostgreSQL backend by name.
Note: the mapping for the procedure name to function id needs to exist, usually to an earlier call to addfunction().
This is the preferred method to call, as function id's can/may change between versions of the backend.
For an example of how this works, refer to org.postgresql.largeobject.LargeObject
name
- Function nameargs
- FastpathArguments to pass to fastpathSQLException
- if name is unknown or if a database-access error occurs.LargeObject
public int getInteger(String name, FastpathArg[] args) throws SQLException
name
- Function nameargs
- Function argumentsSQLException
- if a database-access error occurs or no resultpublic long getLong(String name, FastpathArg[] args) throws SQLException
name
- Function nameargs
- Function argumentsSQLException
- if a database-access error occurs or no resultpublic long getOID(String name, FastpathArg[] args) throws SQLException
name
- Function nameargs
- Function argumentsSQLException
- if a database-access error occurs or no resultpublic byte[] getData(String name, FastpathArg[] args) throws SQLException
name
- Function nameargs
- Function argumentsSQLException
- if a database-access error occurs or no resultpublic void addFunction(String name, int fnid)
This adds a function to our lookup table.
User code should use the addFunctions method, which is based upon a query, rather than hard coding the oid. The oid for a function is not guaranteed to remain static, even on different servers of the same version.
name
- Function namefnid
- Function idpublic void addFunctions(ResultSet rs) throws SQLException
This takes a ResultSet containing two columns. Column 1 contains the function name, Column 2 the oid.
It reads the entire ResultSet, loading the values into the function table.
REMEMBER to close() the resultset after calling this!!
Implementation note about function name lookups:
PostgreSQL stores the function id's and their corresponding names in the pg_proc table. To speed things up locally, instead of querying each function from that table when required, a HashMap is used. Also, only the function's required are entered into this table, keeping connection times as fast as possible.
The org.postgresql.largeobject.LargeObject class performs a query upon it's startup, and passes the returned ResultSet to the addFunctions() method here.
Once this has been done, the LargeObject api refers to the functions by name.
Don't think that manually converting them to the oid's will work. Ok, they will for now, but they can change during development (there was some discussion about this for V7.0), so this is implemented to prevent any unwarranted headaches in the future.
rs
- ResultSetSQLException
- if a database-access error occurs.LargeObjectManager
public int getID(String name) throws SQLException
This returns the function id associated by its name.
If addFunction() or addFunctions() have not been called for this name, then an SQLException is thrown.
name
- Function name to lookupSQLException
- is function is unknown.public static FastpathArg createOIDArg(long oid)
oid
- input oidCopyright © 1997-2020 PostgreSQL Global Development Group. All Rights Reserved.