classmate synonym

of synonyms1. Simplifying SQL statements2. Hide the name and owner of an object3. Remote objects with a bit of distributed database provide location transparency4. Providing public access to objects2.3.2 Synonyms Classification2.3.2.1 Private synonyms1. Create syntax:CREATE [OR REPLACE] synonym [schema.] Synonym_name---> Synonym namesfor [schema.] object_name---> Replace this

modify table spacesAlter user to modify permissions for usersAnalyze using the Analyze command to parse arbitrary tables, indexes, and clusters in the databaseAudit any set auditing options for any database objectAudit system Operation Audit allowedBackup any table permissions to back up any tablesBecome user permissions to switch users stateCommit any table permission to submit tablesCreate any cluster permissions for creating clusters for any userCreate any index permissions for creating inde

resource overheadAlter ROLLBACK segment Modify permissions for rollback segmentsAlter sequence modify the owning sequence permissionAlter session Modify permissions for a database sessionAlter SYTEM permissions to modify database server settingsALTER TABLE permission to modify the owning tableAlter TABLESPACE permissions to modify table spacesAlter user to modify permissions for usersAnalyze using the Analyze command to parse arbitrary tables, indexes, and clusters in the databaseAudit any set

episode resource overheadAlter ROLLBACK segment Modify permissions for rollback segmentsAlter sequence modify the owning sequence permissionAlter session Modify permissions for a database sessionAlter SYTEM permissions to modify database server settingsALTER TABLE permission to modify the owning tableAlter TABLESPACE permissions to modify table spacesAlter user to modify permissions for usersAnalyze using the Analyze command to parse arbitrary tables, indexes, and clusters in the databaseAudit

permissions for usersAnalyze using the Analyze command to parse arbitrary tables, indexes, and clusters in the databaseAudit any set auditing options for any database objectAudit system Operation Audit allowedBackup any table permissions to back up any tablesBecome user permissions to switch users stateCommit any table permission to submit tablesCreate any cluster permissions for creating clusters for any userCreate any index permissions for creating indexes for any userCreate any procedure per

(CHAR (256 )); + ------ + ------- + | HEX (CHAR (256, 0) | HEX (CHAR (256 )) | + ------ + ------- + | 010000 | 010000 | + ------ + ------- +The return value of CHAR () is a binary string. You can use the USING statement to generate a string in the given character set:Mysql> select charset (CHAR (0 × 65), CHARSET (CHAR (0 × 65 USING utf8); mysql> select charset (CHAR (0 × 65 )), CHARSET (CHAR (0 × 65 USING utf8); + ------- + ----------- + | CHARSET (CHAR (0 × 65) | CHARSET (CHAR (0 × 65 USING ut

is activated, the CHAR () result will become NULL.◆ CHAR_LENGTH (str)The return value is the length of the str string, measured in characters. A multi-byte character is counted as a single character. For a five-Byte Character Set, LENGTH () returns 10, while CHAR_LENGTH () returns 5.◆ CHARACTER_LENGTH (str)CHARACTER_LENGTH () is a synonym for CHAR_LENGTH.◆ COMPRESS (string_to_compress)Compress a string. This function requires that MySQL has been comp

you store are less than 20 characters, they are stored according to the actual length. 2. CHAR is more efficient than VARCHAR2. 3. Currently, VARCHAR is a synonym for varchar2. The industry standard VARCHAR type can store null strings, but oracle does not, although it reserves the right to do so in the future. Oracle has developed a data type VARCHAR2, which is not a standard VARCHAR. It changes the feature that can store NULL strings in the varchar

tables and cannot perform DML operations.About rownum:Rownum has a feature that is either equal to 1 or smaller than a value. It cannot be directly equal to or greater than a value. Rownum is usually used for pagination.Exercise: Query between 5th data records and 10th data records:Select first_name, rnum from (select rownum rnum, first_name from s_emp where rownum Split display:SELECT * FROM (SELECT a. *, rownum r FROM S_EMP a WHERE r between 5 AND 10 );Exercise: which employees have higher sa

The Comparison Between mysql and oracle table field definitions indicates that the length of mysql1_levarchar variable-length string VARCHAR [0-65535] is calculated by character length by default, for GBK-Encoded chinese characters, VARCHAR2 [1-4000] VARCHAR is a synonym for VARCHAR2. By default, TINYINTSMALLINTMEDIU is calculated by byte length. Mysql and oracle table field definitions comparison description mysql oracle VARCHAR variable-length strin

, Confirm IndexYou can query the index information in the data dictionary views user_indexes and user_ind_columns.Select IC. index_name, IC. column_name,IC. column_position col_pos, ix. uniquenessFrom user_indexes IX, user_ind_columns ICWhere IC. inde_name = IX. index_nameAnd IC. table_name = 'ployees '; Function-based indexCreate index upper_dept_name_idxOn attributes (upper (department_name ));// However, If you want to ensure that Oracle uses an index instead of a full table scan, you must en

structure. The B-tree structure makes it very convenient and fast to find bitmaps. In addition, bitmap is stored in a compressed format, so the disk space occupied is much smaller than that of B-tree indexes. Synonym (synonyms) A synonym is an alias for another data object. The public synonym is for all users. The private sy