CAD, $B%=%U%H%&%'%"3+H/Ey$N@_7W%G!<%?$r4IM}$9$k(B $B%G!<%?%Y!<%9%7%9%F%`$G$OHG4IM}$N5!G=$,I,?\$G$"$k(B. $BHG4IM}$K$*$$$F$O(B, $BHG$NF3=P4X784IM}$H3FHG$N@8@.;~9o!&:o=|;~9oEy$N(B $B;~4V>pJs4IM}$NN>
pJs$K4X$9$k(B $BLd$$9g$o$;>r7o$r(B, $BCj>]%G!<%?7?$G$"$k!VMzNr7?!W$KIU?o$9$k%*%Z%l!<%?$r(B $BMQ$$$k$3$H$K$h$j5-=R2DG=$G$"$k(B. $B$7$+$7(B, $B!VMzNr7?!W$N%*%Z%l!<%?$NMxMQ5,B'$K(B $B@:DL$7$F$$$k$H$O8B$i$J$$KvC 4QE*M}2r$rB%$9$h$&$JMxMQ $^$7$$(B. $BK\9F$G$O(B, $B$3$N$h$&$JGX7J$N$b$H$K(B, $B%j%l!<%7%g%J%k%G!<%?%Y!<%98@8l(BQBE$B>e$K(B $BF3=P4X78!&;~4V>pJs$K4X$9$kLd$$9g$o$;>r7o$N(B 2$B2A$K$D$$$FJs9p$9$k(B.
In management of engineering design databases, version management is indispensable. We have proposed a version management data model named TVDM, which features management of version derivation relationships and relevant temporal information with the history data type. We also proposed its database language TV-Quel. However, descriptions in TV-Quel sometimes become confusing for naive users who are not familiar with the usage of operators associated with the history data type. As an approach to this problem, we propose a visual query language TVQE. TVQE is based on QBE and features visual specification of historical conditions. We describe TVQE, and explain design and implementation of the prototype TVQE interpreter. We also discuss the result of an experiment which compares TVQE and TV-Quel from the viewpoint of user friendliness.