![]() To run the function, click Run on the toolbar. The specified configuration parameter to be set to the specified value when the function is entered, and then restored to its prior value when the function exits. This is only allowed when the function is declared to return a set. Note: Support from PostgreSQL 8.3 or later.Ī positive number giving the estimated number of rows that the planner should expect the function to return. Larger values cause the planner to try to avoid evaluating the function more often than necessary. If the cost is not specified, 1 unit is assumed for C-language and internal functions, and 100 units for functions in all other languages. If the function returns a set, this is the cost per returned row. If this parameter is specified, the function is not executed when there are null arguments instead a null result is assumed automatically.Ī positive number giving the estimated execution cost for the function, in units of cpu_operator_cost. Indicate that the function always returns null whenever any of its arguments are null. Indicate that the function will return a set of items, rather than a single item. Specify that the function is to be executed with the privileges of the user that created it. ![]() But note that any function that has side-effects must be classified volatile, even if its result is quite predictable, to prevent calls from being optimized away an example is setval(). Relatively few database functions are volatile in this sense some examples are random(), currval(), timeofday(). The function value can change even within a single table scan, so no optimizations can be made. Also note that the current_timestamp family of functions qualify as stable, since their values do not change within a transaction. This is the appropriate selection for functions whose results depend on database lookups, parameter variables (such as the current time zone), etc. The function cannot modify the database, and that within a single table scan it will consistently return the same result for the same argument values, but that its result could change across SQL statements. If this option is given, any call of the function with all-constant arguments can be immediately replaced with the function value. The function cannot modify the database and always returns the same result when given the same argument values that is, it does not do database lookups or otherwise use information not directly present in its argument list. If none of these appear, VOLATILE is the default assumption. These attributes inform the query optimizer about the behavior of the function. For backward compatibility, the name may be enclosed by single quotes. May be SQL, C, internal, or the name of a user-defined procedural language. The name of the language that the function is implemented in. Note: Support from PostgreSQL 8.0 or later. Hint: To customize the view of the editor and find out more features for sql editing, see Editor Advanced Features.Įnter the table columns if the return type is set to TABLE. Compound statements can contain declarations, loops, and other control structure statements. This can be a simple statement such as SELECT or INSERT, or it can be a compound statement written using BEGIN and END. Hint: Once uncheck the Show wizard next time, you can go to Options to enable it.ĭefinition consists of a valid SQL procedure statement. Select the Schema and Return Type from the list.Set the parameter Mode, Type Schema, Type, Name and Default Value under corresponding columns. ![]() Define the parameter(s) of the function.You are allowed not to show the Function Wizard when create new function. The Function Wizard will pop up and it allows you to create a function easily. #Navicat for postgresql basic understanding installTo install the pldbgapi extension for debugging PL/pgSQL functions, you can right-click anywhere in the Object List pane and choose Install pldbgapi Extension.Ĭlick the New Function from the object list toolbar. ![]() Click to open an object list for Function. Many kinds of functions can take or return certain pseudo-types (such as polymorphic types), but the available facilities vary. In addition, every kind of function can return a base type or a composite type.
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