DBISAM与BDE的不同之处(国外英文资料).doc

DBISAM与BDE的不同之处(国外英文资料) The difference with BDE: It should be noted that BDE and DBISAM have several very critical differences, especially when you want to convert the BDE application to DBISAM. Note that all of the comparisons here are assumed to be based on only the BDE available and dBase/FoxPro local databases, for a number of reasons that do not include Access in comparison. BLOB: BDE (in the Paradox database) allow storing BLOB data to a given in the actual data records stored in a BLOB field, unless you store BLOB BLOB to a separate file. DBISAM does not support this operation, but rather, like dBase, stores all BLOB data separately in a separate BLOB file. DBISAM is always in the record is when add or edit a BLOB cache in memory, by contrast, BDE is in commonly the BLOB data more than memory consumption acceptable limits, and save them in a temporary file on disk (acceptable limit is determined by the BDE). Data backup: DBISAM currently has no batch move components, but it is also possible to provide a large number of inserts and updates through SQL inserts and UPDATE statements. Cache update: DBISAM also does not support cache updates. Again, you can easily achieve the same functionality through memory tables and transactions. Parallel operations (multiple users) : Generally speaking, BDE is difficult to set up for multiple users, especially for the Paradox. , the need to deal with the.net file. LCK files and set up local Shared, if set inappropriate data refresh will lead to difficulties, serious when cause data destruction and loss of data. With DBISAM, all locking is done by the operating system without any external configuration files. You definitely dont need for a single user and multi-user do any extra work, all the hard work has been done for you, you only need to do is put on the table is copied to the web server. If the manual refresh is not performed, BDE typically does not provide the latest data in the local cache, so different customers may se