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handling large layouts : use of groups versus instance mosaic

MalcolmWhite

Greetings - first , apology if this isn't the right forum for this : Wondering this scenario : in the situation where someone is working at an upper level layout cell with large amounts of data experiencing significant lag in performing basic layout operations , what is the best manner to handle repeated layout structures in terms of reducing lag time of memory access for data : Groups or mosaics ? mostly trying to learn how groups are handled in the system.  thanks.

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  • Andrew Beckett

    For small numbers of objects, it doesn't matter too much. However, for very large numbers of repeated objects then a mosaic is more efficient. In essence a group (I assume you mean a figGroup in the database) is just a means of creating a relationship between a number of flat objects - so if you have a group with a 100 x 200 instances, you still have 20,000 instances present in the design. If you have a mosaic with 100 x 200 in the array, there's a single database record describing that array, and then it's expanded at rendering time rather than needing expanding in the database.

    There are however some limitations with mosaics if you're using a connectivity-driven flow (such as Virtuoso Layout Suite XL) because that only allow mosaics if the connectivity to every instance in the mosaic is identical (this is a limitation of what can be represented by mosaics in the database rather than a limitation of VLS XL). Also, mosaics have to be an array of instances, whereas a figGroup can contain anything (well, any figure)

    Andrew.

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  • Andrew Beckett

    For small numbers of objects, it doesn't matter too much. However, for very large numbers of repeated objects then a mosaic is more efficient. In essence a group (I assume you mean a figGroup in the database) is just a means of creating a relationship between a number of flat objects - so if you have a group with a 100 x 200 instances, you still have 20,000 instances present in the design. If you have a mosaic with 100 x 200 in the array, there's a single database record describing that array, and then it's expanded at rendering time rather than needing expanding in the database.

    There are however some limitations with mosaics if you're using a connectivity-driven flow (such as Virtuoso Layout Suite XL) because that only allow mosaics if the connectivity to every instance in the mosaic is identical (this is a limitation of what can be represented by mosaics in the database rather than a limitation of VLS XL). Also, mosaics have to be an array of instances, whereas a figGroup can contain anything (well, any figure)

    Andrew.

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