8. Maintaining Databases : How File Names Are Assigned for Tables
 
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How File Names Are Assigned for Tables
A naming algorithm is used to assign underlying file names for tables. There are two columns in the iirelation table used to produce names:
reltid, a unique table identifier assigned in sequential order
reltidx, a unique index identifier associated with each base table
The algorithm for creating the name is as follows:
1. Convert reltid (for base tables) or reltidx (for secondary indexes) to an 8-digit hexadecimal number.
2. Assign letters to each of the resulting hexadecimal digits:
0,1, 2, ..., F is assigned to a, b, c, ..., p
For example, a reltid of 129 converted to an 8-digit hex number is “00000081”. Substituting letters gives a file name of aaaaaaib.tnn, where nn=00, 01, ..., for first (or only) location, second location, and so on.