A Proxy Service for Multi-tenant Elastic Extension Tables - Transactions on Large-Scale-Data-and Knowledge-Centered Systems XX - page 14

OTMQ masterPK 0 ; i . OTMQ type denotes the OTMQ details type (CTT or VET). OTMQ detailsFK
denotes a set stores foreign keys columns

names of the details table. OTMQ swapPK
denotes a row matrix with 2 rows and n columns to store. The

'

rst row stores a
OTMQ swapPK 0 ; i that denotes the column name of a foreign key. This foreign key belongs to
the details table and refers to a primary key in the master table. The second row stores
OTMQ swapPK 1 ; i that denotes a value of the OTMQ swapPK 0 ; i . OTMQ rows denotes a set of
retrieved rows from a VET. OTMQ array denotes a two dimensional array to store the
retrieved rows.

.

5.3 Union Query Algorithm

This algorithm retrieves a combined result-set of two or more tables, whether they are
CTTs, VETs or a combination of CTTs and VETs, and then stores the result-set in an
array. The details of this algorithm are outlined in Algorithm 6.

Denition 6 (Union Query Algorithm). UQ tables denotes a set of CTTs and/or VETs
tables names. UQ colNames denotes a matrix with 1 row and n columns. Each column
in this matrix contains of a set of arbitrary table columns which are related to a table in
UQ tables . UQ W denotes a set of WHERE clauses which are related to the UQ tables and the
columns are ordered according to the table orders of UQ tables . UQ Wi denotes an element
of the set UQ W . UQ rows denotes a set of retrieved rows from a CTT or a VET where each