1 08/06/84 display_mrds_db_population, dmdbp
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3 Syntax as a command: dmdbp path -control_args
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6 Function: This command displays the current tuple count for each
7 relation in the given data base model or submodel view. It can also
8 display population statistics about the vfile for each relation's data.
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11 Arguments:
12 path
13 is the relative or absolute pathname of the data base model or
14 submodel, with or without suffix, that is to have the relation's
15 population statistics displayed. If both a data model and submodel
16 of the same name are in the same directory, then the model will be
17 found if no suffix is given.
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20 Control arguments:
21 -brief, -bf
22 limits the output display to only relation names and their current
23 tuple count. Default
24 -long, -lb
25 displays the average number of tuples selected by index during
26 retrieval.
27 -relation rel_name1 ... rel_nameN
28 specifies that only the population for those relations whose names
29 are given in the rel_nameI list are to be displayed according to the
30 other control arguments. This control_arg must appear after path.
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33 Notes: Version 3 data bases must have been opened at least once for
34 exclusive update. They cannot have secondary index information
35 displayed.
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37 For version 4 data bases, only a DBA may use this command on a secured
38 data base, with the model view. The user must have at least "r" access
39 to the relation model segment and the relation data vfile for those
40 relations in the view presented by "path".
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43 Examples:
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45 display_mrds_db_population test -bf
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47 Opening version 4 data model: >udd>m>jg>dr>test.db
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49 RELATION TUPLES
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51 r001 100
52 r002 100
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54 display_mrds_db_population x001 -long
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57 Displaying version 4 data model: >udd>d>dbmt>ndb>K>x>doc>x001.db
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59 RELATION TUPLES INDEX AVE TUPLES SELECTED
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61 r001 100
62 x001 16
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64 A description of the -long form output follows:
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66 Relation: the name of the relation in the user's view.
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68 Tuples: the number of tuples currently stored as records in the
69 vfile.
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71 Index: the indexed attributes in the relation.
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73 Ave Tuples Selected: the number of tuples that MRDS expects to
74 retrieve when doing a comparison on an indexed attribute. This
75 estimate is based on the number of duplicate keys for that index.