Database Implementation Notes

    Whilst Instant JChem tries to behave the same for all supported databases there are times when the different databases do behave differently. This page summarizes the known differences, and other information specific to the particular databases.

    Please also look at the adminstrator's documentation on supported databases .


    • Once a database column is added its size, scale and type cannot usually be modified. The only exception is that VARCHAR columns can be increased in size (but not decreased).


    • No specific issues have been identified.


    • Oracle 10g's flashback tables (table names begining with BIN) are ignored by IJC.

    JChem cartridge for Oracle

    If the JChem cartridge for Oracle has been installed into the Oracle schema to which IJC is connected then cartridge functions will automatically become enabled. This will allow cartridge indexes on JChem Base and standard tables to be used. The primary benefit in using these table type compared to normal JChemBase tables is that the searching in performed in Oracle, so the memory requirement is transferred from the computer on which IJC is running to the Oracle JChem server.

    Installation, management and use of the Oracle cartridge is not covered here. For details see these topics:

    You should try to ensure that the JChem version used by the JChem cartridge is as close as possible to the version used by IJC. For cartridge indexes on JChem Base tables it is essential that the JChem table versions are the same in the JChem version used by the cartridge and IJC, but for cartridge indexes on standard tables there is some tolerance of differences in versions.

    If using a JChem version prior to 5.1.2 in the JChem cartridge the column name specified when creating a chemical terms column for is ignored and an automatically generated name (CHEMTERM1, CHEMTERM2...) will be used. This does not cause problems, but does result in the column name being different to the one that was specified.

    For indexes on standard tables it is not currently possible to promote the "hidden" JChem fields such as CD_SMILES and CD_FLAGS. Chemical terms columns can be promoted but only through the toolbar action.