1 DISPLAY Requests display of data fields from a database page. An individual DISPLAY command can include only one of the display options shown. If no parameters are specified (you only specify DISPLAY), RdbALTER displays the last object of a PAGE, a DISPLAY, or a DEPOSIT command. 2 Format (B)0q> DISPLAY qwqqqqqqqq>qqqqqqqwqwqqqqqqqqqqqqqqqqqqqqqqwq> mq> page-number qj tq> * qqqqqqqqqqqqqqqqqu tq> STORAGE_AREA qqqqqqu tq> CHECKSUM qqqqqqqqqqu tq> COUNT qqqqqqqqqqqqqu tq> display-data qqqqqqu tq> FREE_SPACE qqqqqqqqu tq> HEADER qqqqqqqqqqqqu tq> display-entry qqqqqu tq> display-index qqqqqu tq> display-line qqqqqqu tq> LOCKED_SPACE qqqqqqu tq> NUMBER qqqqqqqqqqqqu tq> SPACE range qqqqqqqu tq> TIME_STAMP qqqqqqqqu tq> NEXT_AIP qqqqqqqqqqu mq> AIP_ENTRIES qqqqqqqj (B)0display-data = qq> DATA qwqwqqqqqqqqq>qqqqqqqwqwqqqqqqq>qqqqqqwqwq> offset qq> x tq> /DECIMAL qqqqqu tq> /BYTE qqqqqu x x mq> /HEXADECIMAL qj tq> /LONGWORD qu x x mq> /WORD qqqqqj x mq> /ASCII qqwqqqqqq>qqqqqwqqqqqqqqqqqqj mq> : qq> n qj (B)0display-entry = qq> ENTRY qwqqq>qqwqwqqqqqqqqq>qqqqqqqqwqq> tq> n qu tq> * qqqqqqqqqqqqqu mq> * qj tq> ABM qqqqqqqqqqqu tq> LOGICAL_AREA qqu tq> PHYSICAL_AREA qu tq> ALENGTH qqqqqqqu tq> ANAME qqqqqqqqqu tq> TSN qqqqqqqqqqqu tq> RECORD_LENGTH qu mq> INUSE qqqqqqqqqj (B)0display-index = qq> INDEX qwqqq>qqwqwqqqqq>qqqqqwqq> tq> n qu tq> * qqqqqqu mq> * qj tq> LENGTH qu mq> OFFSET qj (B)0display-line = qq> LINE qwqqq>qqwqwqqqqqqqq>qqqqqqqwqq> tq> n qu tq> * qqqqqqqqqqqu mq> * qj mq> RECORD_TYPE qj (B)0range = wq> * qqqqqqqqqqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqwq> mq> lower-data-page-number qwqqqqqqqqqqqqqqqq>qqqqqqqqqqqqqqqqqwj mq> : qq> higher-data-page-number qj 2 Arguments 3 page-number Identifies the page whose information you want to display. The current page is the default. 3 *_(asterisk) Displays the entire page. 3 STORAGE_AREA Displays the 2-byte storage area identification. 3 CHECKSUM Displays the 4-byte page checksum field. 3 COUNT Displays the 2-byte field showing the number of line index entries. If this number is 1, the page contains only the SYSTEM record. 3 DATA_offset Displays the number of bytes specified. If you do not specify the HEXADECIMAL or DECIMAL qualifier, the default radix is assumed. See the help entry for the RADIX command for information on how to set a default radix by using the RADIX command. The value you specify for n is the number of bytes you want to display. The maximum value that can be specified for n is the size of the page minus the offset. If you do not specify n, 1 byte is displayed. The BYTE, LONGWORD, and WORD qualifiers cannot be used with the ASCII qualifier. 3 FREE_SPACE Displays the 2-byte field indicating how much free space remains on the page. 3 HEADER Displays the entire page header. 3 ENTRY ENTRY n ENTRY * Refers to an area inventory page (AIP) entry on the database page. If you specify a value for n, it must be a number between zero and the number of AIP entries. If you specify the asterisk (*) parameter, the information you request with the other DISPLAY ENTRY parameters is displayed for each AIP entry on the database page. 3 asterisk Displays the same information that is displayed when you specify the ABM, LOGICAL_AREA, PHYSICAL_AREA, ALENGTH, ANAME, TSN, RECORD_LENGTH, and INUSE parameters. 3 ABM Displays the first area bit map (ABM) page for the specified area inventory page (AIP) entry. The value is contained in a longword. 3 LOGICAL_AREA Displays the number of the logical area of an AIP entry. The value is contained in a word. 3 PHYSICAL_AREA Displays the number of the physical area of an AIP entry. The value is contained in a word. 3 ALENGTH Displays the length of the name of the logical area of an AIP entry. The value is contained in 1 byte. The name of the logical area can be from 1 to 31 bytes in length. 3 ANAME Displays the name of the logical area of an AIP entry. The value is contained in a 31-character text field. 3 TSN Displays the value of the last transaction sequence number (TSN) to enable snapshots for the logical area of an AIP entry. NOTE Beginning in Oracle Rdb V7.0, Oracle Rdb stores any transaction sequence number that is larger than a longword by using both the TSN field on the page and the page TSN base. Oracle Rdb calculates the actual TSN by applying a formula to these two values. Oracle Corporation recommends that you do not change a TSN value that is larger than a longword. When a TSN is larger than a longword, a nonzero number is stored in the page TSN base (the page tail). The following example shows the location of the page TSN and the page TSN base: 000A 00000003 0000 page 3, physical area 10 9D091204 0006 checksum = 9D091204 009A2C0F ED786D2E 000A time stamp = 23-MAY-1996 09:08:53.36 0000 03C4 0012 964 free bytes, 0 locked 0001 0016 1 line 0005 03E4 0018 line 0: offset 03E4, 5 bytes page TSN -----> 00000000 001C line 0: TSN 0 . . . 2001 03E4 line 0 (10:3:0) SYSTEM record 00 0001 03E6 1 byte in 0 sets/dynamic items 0000000000 03E9 padding '.....' FFFFFFFF 03EE snap page pointer -1 00000000 03F2 snap pointer TSN 0 0000 03F6 MBZ '..' 00000000 03F8 page sequence number 0 page TSN base -------> 0000 03FC page TSN base 0 0000 03FE MBZ '..' 3 RECORD_LENGTH Displays the value for the length of the record size for an AIP entry. The length is expressed in bytes. The RECORD_LENGTH value is contained in a word. 3 INUSE Displays the AIP entry's in-use flag. The value is contained in 1 byte. NOTE In the next two parameters, the integers denoting INDEX and LINE are zero based. For example, INDEX 0 refers to the first index, and LINE 3 refers to the fourth line. The integer n is optional. The present value of the relevant pointer is the default. References to INDEX and LINE are invalid if the current page is a space area management (SPAM) page. 3 INDEX_n Displays the offset field, the length field, or both from the line index indicated by n. For example, if you enter DISPLAY INDEX 3 OFFSET, the offset address field from the fourth line index is displayed. If you enter DISPLAY INDEX 3 LENGTH, the length field from the fourth line index is displayed. If you enter either DISPLAY INDEX 3 or DISPLAY INDEX 3 *, both the offset and the length fields from the fourth line index are displayed. 3 INDEX_asterisk INDEX * Displays the offset field and the length field for all index nodes on a page. 3 LINE_n Displays information from an individual storage segment. You can display the RECORD_TYPE field or the entire content of the storage segment line indicated by n. 3 LINE_asterisk LINE * Displays information from all storage segments on a page. 3 LOCKED_SPACE Displays the 2-byte field indicating how much free space is allocated for exclusive use by a recovery unit. 3 NUMBER Shows the 4-byte page number field. 3 SPACE SPACE range Displays SPAM entries; it is valid only if the current page is a SPAM page. The SPACE parameter is the only option that you can use in DISPLAY and DEPOSIT commands that access a SPAM page. The optional range value can be an asterisk (*), referring to all entries, or a set of consecutive entries that you describe as follows: lower-data-page-number[:higher-data-page-number] When you specify a range, you reduce the output display. The specified range of SPAM entries is included in the display; other SPAM entries outside your specified range can also be included in the display. Each entry on a SPAM page consists of 2 bits, containing a value 0 through 3 that represents a fullness threshold. For example, if the nth SPAM entry contains a 2, it means that the nth data page in the interval has reached a percentage of fullness greater than the second threshold for the area, but less than or equal to the third threshold. 3 TIME_STAMP Displays the 8-byte time stamp field. 3 NEXT_AIP Displays the page number of the next area inventory page (AIP). 3 AIP_ENTRIES Displays a value for the number of area inventory page (AIP) entries on the current area inventory page. 2 Examples Example 1 The following example displays page 94 of area 1: RdbALTER> AREA 1 RdbALTER> DISPLAY 94 0001 0000005E 0000 page 94, physical area 1 7B429FB0 0006 checksum = 7B429FB0 0093249F 9EBDB820 000A time stamp = 14-FEB-1990 10:42:35.81 0000 0004 0012 4 free bytes, 0 locked FFFFFFFF 0016 next area bit map page -1 00000000 001A max set bit index 0 00000000 001E MBZ '....' 00001E60 0022 bitvector count 7776 00000000000000000000000000000000 0026 bitvector '................' :::: (59 duplicate lines) 000000000000000000000000 03E6 bitvector '............' 00000000 03F2 MBZ '....' 801F 03F6 bitmap page for logical area 31 0000000000000000 03F8 MBZ '........' Example 2 The following example displays the number of the current storage area: RdbALTER> DISPLAY STORAGE_AREA 0001 0000 area 1 Example 3 This example displays the number of AIP entries on area 1, page 2 of the mf_personnel database, and the value of the highest snapshot-enabled TSN of AIP entry 14. This example also displays the number of the next AIP in the current storage area. RdbALTER> AREA 1 PAGE 2 RdbALTER> DISPLAY AIP_ENTRIES 0010 0022 16 logical area entries RdbALTER> DISPLAY ENTRY 14 TSN entry #14 00000001 0386 snaps enabled TSN 1 RdbALTER> DISPLAY NEXT_AIP 00000003 0016 next area inventory page 3 See the Oracle Rdb Guide to Database Maintenance for more examples of how to use the DISPLAY command.