set @variable = expression [, @variable = expression...]

 

allows multiple variable assignments in one statement. The set @variable = expression command is an identical -- and an alternative -- command to select @variable = expression in Transact-SQL.

expression

includes constant, function, any combination of constants, and functions connected by arithmetic or bitwise operators, or a subquery.

 

 

set ansi_datatypes {on | off}

 

determines how Adaptive Server interprets the timestamp keyword:

By default, ansi_datatypes is set off, causing Adaptive Server to interpret timestamp as the Transact-SQL timestamp user-defined datatype. You must specify the ansi_timestamp type to create or reference ANSI-compliant timestamp types.

When ansi_datatypes is set on, Adaptive Server interprets timestamp as the ANSI-compliant timestamp system datatype. You must specify the syb_timestamp type to create or reference the Transact-SQL timestamp user-defined datatype.

 

 

set ansinull {on | off}

 

impacts on both aggregate and comparison behaviors:

Aggregate behavior

ansinull determines whether evaluation of NULL-valued operands in aggregate functions is compliant with the ANSI SQL standard. If you use set ansinull on, Adaptive Server generates a warning when an aggregate function eliminates a null-valued operand from the calculation.

For example, if you perform the following query on the titles table with set ansinull off (the default value):

select max(total_sales) from titles

Adaptive Server returns:

-----------

            22246

However, if you perform the same query with set ansinull on, Adaptive Server returns the same value and an error message because the total_sales column contains NULL values:

-----------

                                    22246

Warning - null value eliminated in set function

This message indicates that some entries in total_sales contain NULL instead of a real amount, so you do not have complete data on total sales for all books in this table. However, of the available data, the value returned is the highest.

 

Comparison behavior

The SQL standard requires that if either one of the two operands of an equality comparison is NULL, the result is UNKNOWN. Transact-SQL treats NULL values differently. If one of the operands is a column, parameter, or variable, and the other operand is the NULL constant or a parameter or variable whose value is NULL, the result is either TRUE or FALSE:

Sybase NULL mode - "val = NULL" is true when "val" is NULL

 

ANSI NULL mode - "val = NULL" is unknown when "val" is NULL

 

The ANSI rule for the where and on clauses return rows that are true, and rejects rows that are both false and unknown.

The ANSI rule for a check constraint rejects values that are false. For this reason, unknown or true results are not rejected.

If you:

Enable ansinull mode - do not use the Sybase NULL comparisons (val = NULL

or val != NULL).

Expect to use ANSI-null mode during insert and update - do not use the Sybase NULL comparisons in check constraints.

Instead, use the ANSI IS NULL or IS NOT NULL syntax to prevent from having unexpected results.

 

 

set ansi_permissions {on | off}

 

determines whether ANSI SQL permission requirements for delete and update statements are checked. The default is off. Table 1-36 summarizes permission requirements:

Table 1-36: Permissions required for update and delete Command

Permissions required with set ansi_permissions off

Permissions required with set ansi_permissions on

Update

update permission on columns where values are being set

update permission on columns where values are being set

select permission on all columns appearing in where clause

select permission on all columns on right side of set clause

Delete

delete permission on table

delete permission on table

select permission on all columns appearing in where clause

 

 

set arithabort {on | off}

 

determines how Adaptive Server behaves when an arithmetic error occurs. The two arithabort options, arithabort arith_overflow and arithabort numeric_truncation, handle different types of arithmetic errors. You can set each option independently or set both options with a single set arithabort on or set arithabort off statement.

 

set arithabort arith_overflow {on | off}

 

arithabort arith_overflow specifies Adaptive Server's behavior following a divide-by-zero error or a loss of precision during an explicit or implicit datatype conversion. This type of error is serious. The default setting, arithabort arith_overflow on, rolls back the entire transaction in which the error occurs. If the error occurs in a batch that does not contain a transaction, arithabort arith_overflow on does not roll back earlier commands in the batch; however, Adaptive Server does not execute any statements in the batch that follow the error-generating statement.

If you set arithabort arith_overflow off, Adaptive Server aborts the statement that causes the error, but continues to process other statements in the transaction or batch.

 

set arithabort [arith_overflow | numeric_truncation]{on | off}

 

arithabort numeric_truncation specifies Adaptive Server's behavior following a loss of scale by an exact numeric type during an implicit datatype conversion. (When an explicit conversion results in a loss of scale, the results are truncated without warning.) The default setting, arithabort numeric_truncation on, aborts the statement that causes the error, but Adaptive Server continues to process other statements in the transaction or batch. If you set arithabort numeric_truncation off, Adaptive Server truncates the query results and continues processing.

 

set arithignore [arith_overflow] {on | off}

 

determines whether Adaptive Server displays a message after a divide-by-zero error or a loss of precision. By default, the arithignore option is set to off. This causes Adaptive Server to display a warning message after any query that results in numeric overflow. To have Adaptive Server ignore overflow errors, use set arithignore on. You can omit the optional arith_overflow keyword without any effect.

 

set bulk array size number

 

establishes the number of rows that are buffered in local server memory before being transferred using the bulk copy interface.

Use this option only with Component Integration Services for transferring rows to a remote server using select into.

View your current setting using the @@bulkarraysize global variable.

number indicates the number of rows to buffer. If the rows being transferred contain text, image or java ADTs, then the bulk copy interface ignores the current setting for array size and uses a value of 1. Also, the array size actually used will never exceed the value of @@bulkbatchzise. If @@bulkbatchsize is smaller than array size, then the smaller value is used.

The initial value of the array size is inherited by new connections from the current setting of the configuration property cis bulk insert array size, which defaults to 50. Setting this value to 0 will reset the value to the default.

 

set bulk batch size number

 

establishes the number of rows transferred to a remote server via select into proxy_table when the bulk interface is used. The bulk interface is available to all Adaptive Servers, as well as DirectConnect for Oracle version 12.5.1.

Use this option only with Component Integration Services for transferring rows to a remote server using select into.

View your current setting using the @@bulkbatchsize global variable.

The bulk interface allows a commit after a specified number of rows. This allows the remote server to free any log space being consumed by the bulk transfer operation, and enables the transfer of large data sets from one server to another without filling the transaction log.

The initial value of the batch size is inherited by new connections from the current setting of the configuration property cis bulk insert batch size, which by default is 0. A value of 0 indicates that no rows should be committed until after the last row is transferred.

 

set chained {on | off}

 

begins a transaction just before the first data retrieval or data modification statement at the beginning of a session and after a transaction ends. In chained mode, Adaptive Server implicitly executes a begin transaction command before the following statements: delete, fetch, insert, open, select, and update. You cannot execute set chained within a transaction.

 

 

set close on endtran {on | off}

 

causes Adaptive Server to close all cursors opened within a transaction at the end of that transaction. A transaction ends by the use of either the commit or rollback statement. However, only cursors declared within the scope that sets this option (stored procedure, trigger, and so on) are affected.

 

set char_convert {off | on [with {error | no_error}] |

    charset [with {error | no_error}]}

 

enables or disables character set conversion between Adaptive Server and a client. If the client is using Open Client DB-Library release 4.6 or later, and the client and server use different character sets, conversion is turned on during the login process and is set to a default based on the character set the client is using. You can also use set char_convert charset to start conversion between the server character set and a different client character set.

charset can be either the character set's ID or a name from syscharsets with a type value of less than 2000.

set char_convert off turns conversion off so that characters are sent and received unchanged. set char_convert on turns conversion on if it is turned off. If character set conversion was not turned on during the login process or by the set char_convert command, set char_convert on generates an error message.

If you request character set conversion with set char_convert charset, and Adaptive Server cannot perform the requested conversion, the conversion state remains the same as it was before the request. For example, if conversion is set to off prior to the set char_convert charset command, conversion remains turned off if the request fails.

When the with no_error option is included, Adaptive Server does not notify an application when characters from Adaptive Server cannot be converted to the client's character set. Error reporting is initially turned on when a client connects with Adaptive Server: if you do not want error reporting, you must turn it off for each session with set char_convert {on | charset} with no_error. To turn error reporting back on within a session, use set char_convert {on | charset} with error.

Whether or not error reporting is turned on, the bytes that cannot be converted are replaced with ASCII question marks (?).

 

 

set cis_rpc_handling {on | off}

 

determines whether Component Integration Services handles outbound remote procedure call (RPC) requests by default.

 

set clientapplname application_name

 

assigns an application an individual name. This is useful for differentiating among clients in a system where many clients connect to Adaptive Server using the same application name. After you assign a new name to an application, it appears in the sysprocesses table under the new name.

 

set clienthostname  host_name

 

assigns a host an individual name. This is useful for differentiating among clients in a system where many clients connect to Adaptive Server using the same host name. After you assign a new name to a host, it appears in the sysprocesses table under the new name.

 

set clientname client_name

 

assigns a client an individual name. This is useful for differentiating among clients in a system where many clients connect to Adaptive Server using the same client name. After you assign a new name to a user, they appear in the sysprocesses table under the new name.

 

set cursor rows number for cursor_name

 

causes Adaptive Server to return the number of rows for each cursor fetch request from a client application. The number can be a numeric literal with no decimal point or a local variable of type integer. If the number is less than or equal to zero, the value is set to 1. You can set the cursor rows option for a cursor, whether it is open or closed. However, this option does not affect a fetch request containing an into clause. cursor_name specifies the cursor for which to set the number of rows returned.

 

set datefirst number

 

uses numeric settings to specify the first day of the week. The us_english language default is Sunday. To set the first day of the week, use the following:

To set the first day of the week as

Use this setting

Monday

1

Tuesday

2

Wednesday

3

Thursday

4

Friday

5

Saturday

6

Sunday (us_english language default)

7

Regardless of which day you set as the first day of the week, the value of that first day becomes 1. This value is not the same as the numeric setting you use in set datefirst n. For example, if you set Sunday as your first day of the week, its value is 1. If you set Monday as your first day of the week, Monday's value becomes 1. If you set Wednesday as your first day of the week, Wednesday's value becomes 1, and so on.

 

 

set dateformat format,

   

sets the order of the date parts month/day/year for entering datetime , smalldatetime, date or time data. Valid arguments are mdy, dmy, ymd, ydm, myd, and dym. The us_english language default is mdy.

 

 

set explicit_transaction_required [true | false]

 

when set to true, causes any attempts to start an implicit transaction, or send an RPC to a remote server outside a transaction, to fail.All other commands succeed.

 

set fipsflagger {on | off}

 

determines whether Adaptive Server displays a warning message when Transact-SQL extensions to entry-level ANSI SQL are used. By default, Adaptive Server does not tell you when you use nonstandard SQL. This option does not disable SQL extensions. Processing completes when you issue the non-ANSI SQL command.

 

set flushmessage {on | off}

 

determines when Adaptive Server returns messages to the user. By default, messages are stored in a buffer until the query that generated them is completed or the buffer is filled to capacity. Use set flushmessage on to return messages to the user immediately, as they are generated.

 

set forceplan {on | off}

 

causes the query optimizer to use the order of the tables in the from clause of a query as the join order for the query plan. forceplan is generally used when the optimizer fails to choose a good plan. Forcing an incorrect plan can have severely bad effects on I/O and performance.

 

set identity_insert [database.[owner.]]table_name {on | off}

 

determines whether explicit inserts into a table's IDENTITY column are allowed. (Updates to an IDENTITY column are never allowed.) This option can be used only with base tables. It cannot be used with views or set within a trigger.

Setting identity_insert table_name on allows the table owner, Database Owner, or System Administrator to explicitly insert a value into an IDENTITY column. Inserting a value into the IDENTITY column allows you to specify a seed value for the column or to restore a row that was deleted in error. Unless you have created a unique index on the IDENTITY column, Adaptive Server does not verify the uniqueness of the inserted value; you can insert any positive integer.

The table owner, Database Owner, or System Administrator can use the set identity_insert table_name on command on a table with an IDENTITY column to enable the manual insertion of a value into an IDENTITY column. However, only the following users can actually insert a value into an IDENTITY column, when identity_insert is on:

Table owner

Database Owner:

if granted explicit insert permission on the column by the table owner

impersonating the table owner by using the setuser command

Setting identity_insert table_name off restores the default behavior by prohibiting explicit inserts to IDENTITY columns. At any time, you can use set identity_insert table_name on for a single database table within a session.

 

set identity_update table_name {on | off}

 

With set identity_update on, you can explicitly update the value of the IDENTITY column on a table. identity_update changes the identity column value for the qualified rows. When identity_update is enabled, you can update the identity value to any value greater than 0. However, if the input value is greater than the identity burn max value, a new set of ID values is allocated, and the identity burn max value on the OAM page is updated accordingly. If update is included in a transaction, the new identity burn max value cannot be rolled back. You can use syb_identity to point to the identity column for update. For example:

update table_name set syb_identity = value

where clause

Adaptive Server does not check for duplicates entries or verify that entries are unique. You can update an existing value to any positive integer within the range allowed by the column's declared precision. You can check for duplicate entries by creating a unique index on the identity column

 

set jtc {on | off}

 

toggles join transitive closure. If tableA colA equals tableB colB and tableB colB equals

tableC colC, then the ASE knows tableA colA equals tableC colC.

 

 

Set language language_name

 

is the official name of the language that displays system messages. The language must be installed on Adaptive Server. The default is us_english.

 

set lock { wait [ numsecs ] | nowait }

lock wait

specifies the length of time that a command waits to acquire locks before aborting and returning an error.

numsecs

specifies the number of seconds a command is to wait to acquire a lock. Valid values are from 0 to 2147483647, the maximum value for an integer.

lock nowait

specifies that if a command cannot acquire a lock immediately, it returns an error and fails. set lock nowait is equivalent to set lock wait 0.

 

Set nocount {on | off}

 

controls the display of rows affected by a statement. set nocount on disables the display of rows; set nocount off reenables the count of rows.

 

Set noexec {on | off}

 

compiles each query but does not execute it. noexec is often used with showplan. After you set noexec on, no subsequent commands are executed (including other set commands) until you set noexec off.

compiles each subsequent query but does not execute it. set fmtonly on is often used with showplan for troubleshooting. Set noexec on immediately after executing a query. After you set noexec on, no subsequent commands are executed (including other set commands) until you set noexec off. set noexec can be used in stored procedures.

 

 

 

set offsets {select, from, order, compute, table,

    procedure, statement, param, execute} {on | off}

 

returns the position of specified keywords (with relation to the beginning of the query) in Transact-SQL statements. The keyword list is a comma-separated list that can include any of the following Transact-SQL constructs: select, from, order, compute, table, procedure, statement, param, and execute. Adaptive Server returns offsets if there are no errors. This option is used in Open Client DB-Library only.

 

set parallel_degree number

 

specifies an upper limit for the number of worker processes used in the parallel execution of a query. This number must be less than or equal to the number of worker processes per query, as set by the max parallel degree configuration parameter. The @@parallel_degree global variable stores the current setting.

 

Set parse only {on | off}

 

checks the syntax of each query and returns any error messages without compiling or executing the query. Do not use parseonly inside a stored procedure or trigger.

 

set plan {dump | load } [group_name] {on | off}

 

plan

introduces an abstract plan command.

dump

enables or disables capturing abstract plans for the current connection. If a group_name is not specified, the plans are stored in the default group, ap_stdout.

load

enables or disables loading abstract plans for the current connection. If a group_name is not specified, the plans are loaded from the default group, ap_stdin.

group_name

is the name of the abstract plan group to use for loading or storing plans.

 

set plan exists check {on | off}

 

when used with set plan load, stores hash keys for up to 20 queries from an abstract plan group in a per-user cache.

 

set plan replace {on | off}

 

enables or disables replacing existing abstract plans during plan capture mode. By default, plan replacement is off.

 

 

set prefetch [on|off]

 

enables or disables large I/Os to the data cache.

 

set process_limit_action {abort | quiet | warning}

 

specifies whether Adaptive Server executes parallel queries when an insufficient number of worker processes is available. Under these circumstances, when process_limit_action is set to quiet, Adaptive Server silently adjusts the plan to use a degree of parallelism that does not exceed the number of available processes. If process_limit_action is set to warning when an insufficient number of worker processes are available, Adaptive Server issues a warning message when adjusting the plan; and if process_limit_action is set to abort, Adaptive Server aborts the query and issues an explanatory message an insufficient number of worker processes are available.

 

Set procid

 

returns the ID number of the stored procedure to Open Client DB-Library/C (not to the user) before sending rows generated by the stored procedure.

 

 

set proxy login_name

 

allows you to assume the permissions, login name, and suid (server user ID) of login_name. For login_name, specify a valid login from master..syslogins, enclosed in quotation marks. To revert to your original login name and suid, use set proxy with your original login_name.

Without explicit permission, neither the "sa_role" nor the "sso_role" can issue the set proxy login_name command. To use set proxy login_name, any user, including the System Security Officer, must have permission explicitly granted by the System Security Officer. ­

 

set quoted_identifier {on | off}

 

determines whether Adaptive Server recognizes delimited identifiers. By default, quoted_identifier is off and all identifiers must conform to the rules for valid identifiers. If you use set quoted_identifier on, you can use table, view, and column names that begin with a nonalphabetic character, include characters that would not otherwise be allowed, or are reserved words, by enclosing the identifiers within double quotation marks. Delimited identifiers cannot exceed 28 bytes, may not be recognized by all front-end products, and may produce unexpected results when used as parameters to system procedures.

When quoted_identifier is on, all character strings enclosed within double quotes are treated as identifiers. Use single quotes around character or binary strings.

 

set role {"sa_role" | "sso_role" | "oper_role" |

    role_name [with passwd "password"]} {on | off}

role

turns the specified role on or off during the current session. When you log in, all system roles that have been granted to you are turned on. Use set role role_name off to turn a role off, and set role role_name on to turn it back on again, as needed. System roles are "sa_role", "sso_role", and "oper_role". If you are not a user in the current database, and if there is no "guest" user, you cannot set sa_role off, because there is no server user ID for you to assume.

role_name

is the name of any user-defined role created by the System Security Officer. User-defined roles are not turned on by default. To set user-defined roles to activate at login, the user or the System Security Officer must use set role on.

with passwd

specifies the password to activate the role. If a user-defined role has an attached password, you must specify the password to activate the role.

 

set rowcount number

 

causes Adaptive Server to stop processing the query (select, insert, update, or delete)after the specified number of rows are affected. The number can be a numeric literal with no decimal point or a local variable of type integer. To turn this option off, use: set rowcount 0

 

set scan_parallel_degree number

 

specifies the maximum session-specific degree of parallelism for hash-based scans (parallel index scans and parallel table scans on nonpartitioned tables). This number must be less than or equal to the current value of the max scan parallel degree configuration parameter. The @@scan_parallel_degree global variable stores the current setting.

 

Set self_recursion {on | off}

 

determines whether Adaptive Server allows triggers to cause themselves to fire again (this is called self recursion). By default, Adaptive Server does not allow self recursion in triggers. You can turn this option on only for the duration of a current client session; its effect is limited by the scope of the trigger that sets it. For example, if the trigger that sets self_recursion on returns or causes another trigger to fire, this option reverts to off. This option works only within a trigger and has no effect on user sessions.

 

 

set session authorization login_name

 

is identical to set proxy, with this exception: set session authorization follows the SQL standard, while set proxy is a Transact-SQL extension.

 

Set showplan  {on|off}

 

generates a description of the processing plan for the query. The results of showplan are of use in performance diagnostics. showplan does not print results when it is used inside a stored procedure or trigger. For parallel queries, showplan output also includes the adjusted query plan at runtime, if applicable.

 

 

set sort_merge {on | off}

 

enables or disables the use of sort-merge joins during a session.

 

Set sort resources {on|off}

 

generates a description of the sorting plan for a create index statement. The results of sort_resources are of use in determining whether a sort operation will be done serially or in parallel. When sort_resouces is on, Adaptive Server prints the sorting plan but does not execute the create index statement.

 

set statistics io {on | off}

 

displays the following statistics information for each table referenced in the statement:

the number of times the table is accessed (scan count)

the number of logical reads (pages accessed in memory)

and the number of physical reads (database device accesses)

For each command, statistics io displays the number of buffers written.

If Adaptive Server has been configured to enforce resource limits, statistics io also displays the total I/O cost.

 

set statistics subquerycache {on | off}

 

displays the number of cache hits, misses, and the number of rows in the subquery cache for each subquery.

 

set statistics time {on | off}

 

displays the amount of time Adaptive Server used to parse and compile for each command. For each step of the command, statistics time displays the amount of time Adaptive Server used to execute the command. Times are given in milliseconds and timeticks, the exact value of which is machine-dependent.

 

set statistics simulate { on | off }

 

specifies that the optimizer should use simulated statistics to optimize the query.

 

set strict_dtm_enforcement {on | off}

 

determines whether the server propagates transactions to servers that do not support Adaptive Server transaction coordination services. The default value is inherited from the value of the strict dtm enforcement configuration parameter.

 

set string_rtruncation {on | off}

 

determines whether Adaptive Server raises a SQLSTATE exception when an insert or update command truncates a char, unichar, varchar or univarchar string. If the truncated characters consist only of spaces, no exception is raised. The default setting, off, does not raise the SQLSTATE exception, and the character string is silently truncated.

 

set table count number

 

sets the number of tables that Adaptive Server considers at one time while optimizing a join. The default used depends on the number of tables in the join:

Tables joined

Tables considered at a time

2 – 25

4

26 – 37

3

38 – 50

2

Valid values are 0 - 8. A value of 0 resets the default behavior. A value greater than 8 defaults to 8. table count may improve the optimization of certain join queries, but it increases the compilation cost.

 

set textsize {number}

 

specifies the maximum size in bytes of text or image type data that is returned with a select statement. The @@textsize global variable stores the current setting. To reset textsize to the default size (32K), use: set textsize 0

The default setting is 32K in isql. Some client software sets other default values.

 

set transaction isolation level {

    [ read uncommitted | 0 ] |

    [ read committed | 1 ] |

    [ repeatable read | 2 ]|

    [ serializable | 3 ] }

 

 

sets the transaction isolation level for your session. After you set this option, any current or future transactions operate at that isolation level.

read uncommitted | 0

scans at isolation level 0 do not acquire any locks. Therefore, the result set of a level 0 scan may change while the scan is in progress. If the scan position is lost due to changes in the underlying table, a unique index is required to restart the scan. In the absence of a unique index, the scan may be aborted.

By default, a unique index is required for a level 0 scan on a table that does not reside in a read-only database. You can override this requirement by forcing the Adaptive Server to choose a nonunique index or a table scan, as follows:

select * from table_name (index table_name)

Activity on the underlying table may cause the scan to be aborted before completion.

read committed | 1

By default, Adaptive Server's transaction isolation level is read committed or 1, which allows shared read locks on data.

repeatable read | 2

prevents nonrepeatable reads.

serializable | 3

specify isolation level 3, Adaptive Server applies a holdlock to all select and readtext operations in a transaction, which holds the queries' read locks until the end of that transaction. If you also set chained mode, that isolation level remains in effect for any data retrieval or modification statement that implicitly begins a transaction.

 

 

 

set transactional_rpc {on | off}

 

controls the handling of remote procedure calls. If this option is set to on, when a transaction is pending, the RPC is coordinated by Adaptive Server. If this option is set to off, the remote procedure call is handled by the Adaptive Server site handler. The default value is inherited from the value of the enable xact coordination configuration parameter.