Dbstl container specific notes

Dbstl container specific + notes

@@ -40,12 +42,12 @@

- db_vector specific notes + db_vector specific notes
- Associative container specific notes + Associative container specific notes

@@ -54,69 +56,99 @@

db_vector specific notes

+
+ Set the DB_RENUMBER flag in the database + handle if you want + db_vector<> to + work like std::vector or + std::deque. Do not set + DB_RENUMBER if you want + db_vector<> to + work like std::list. Note + that without DB_RENUMBER set, + db_vector<> can + work faster. +

- Set the DB_RENUMBER flag in the database handle if you want - db_vector<> to work like - std::vector or std::deque. Do not set - DB_RENUMBER if you want db_vector<> to work like - std::list. Note that without DB_RENUMBER set, - db_vector<> can work faster. -
+ For example, to construct a fast + std::queue/std::stack object, you only need a + db_vector<> + object whose database handle does not have + DB_RENUMBER set. Of course, if the database + handle has DB_RENUMBER set, it still works for + this kind of scenario, just not as fast. +

- For example, to construct a fast std::queue/std::stack object, you only need a - db_vector<> object whose database handle does not have - DB_RENUMBER set. Of course, if the database handle has DB_RENUMBER set, it - still works for this kind of scenario, just not as fast. -
+ db_vector does not check + whether DB_RENUMBER is set. If you do not set + it, db_vector<> will + not work like + std::vector<>/std::deque<> with regard + to operator[], because the indices are not + maintained in that case. +

- db_vector does not check whether DB_RENUMBER is set. If - you do not set it, db_vector<> will not work like - std::vector<>/std::deque<> with regard to operator[], because the - indices are not maintained in that case. -
-
- You can find example code showing how to use this feature in the - StlAdvancedFeaturesExample::queue_stack() method. -
+ You can find example code showing how to use + this feature in the + StlAdvancedFeaturesExample::queue_stack() + method. +
+
+ Just as is the case with + std::vector, + inserting/deleting in the middle of a + db_vector is slower + than doing the same action at the end of the + sequence. This is because the underlying DB_RECNO + DB (with the DB_RENUMBER flag set) is relatively + slow when inserting/deleting in the middle or the + head — it has to update the index numbers of + all the records following the one that was + inserted/deleted. If you do not need to keep the + index ordered on insert/delete, you can use + db_map instead. +

- Just as is the case with std::vector, inserting/deleting in - the middle of a db_vector is slower than doing the same - action at the end of the sequence. This is because the underlying DB_RECNO DB (with - the DB_RENUMBER flag set) is relatively slow when inserting/deleting in the middle - or the head — it has to update the index numbers of all the records following - the one that was inserted/deleted. If you do not need to keep the index ordered on - insert/delete, you can use db_map instead. -
-
- db_vector also contains methods inherited from - std::list and std::deque, - including std::list<>'s unique methods - remove(), remove_if(), - unique(), merge(), - sort(), reverse(), and - splice(). These use the identical semantics/behaviors - of the std::list<> methods, although - pushing/deleting at the head is slower than the - std::deque and std::list - equivalent when there are quite a lot of elements in the database. -
+ db_vector also contains + methods inherited from + std::list and + std::deque, including + std::list<>'s + unique methods remove(), + remove_if(), + unique(), + merge(), + sort(), + reverse(), and + splice(). These use + the identical semantics/behaviors of the + std::list<> + methods, although pushing/deleting at the head is + slower than the + std::deque and + std::list equivalent + when there are quite a lot of elements in the + database. +
-
- You can use std::queue, - std::priority_queue and std::stack - container adapters with db_vector; they work with db_vector - even without DB_RENUMBER set. -
+
+ You can use std::queue, + std::priority_queue and + std::stack container + adapters with db_vector; + they work with db_vector even without + DB_RENUMBER set. +

@@ -125,24 +157,32 @@

Associative container specific notes

- db_map contains the union of method set from - std::map and hash_map, but there are some - methods that can only be called on containers backed by DB_BTREE or - DB_HASH databases. You can call - db_map<>::is_hash() to figure out the type of the backing - database. If you call unsupported methods then an InvalidFunctionCall exception is thrown. -

- These are the DB_BTREE specific methods: upper_bound(), - lower_bound(), key_comp(), - and value_comp(). The DB_HASH specific methods are - key_eq(), hash_funct(). -

+ db_map contains the union of method + set from std::map and + hash_map, but there are some + methods that can only be called on containers backed by + DB_BTREE or + DB_HASH databases. You can call + db_map<>::is_hash() to + figure out the type of the backing database. If you call + unsupported methods then an InvalidFunctionCall exception + is thrown. +

+ These are the DB_BTREE specific + methods: upper_bound(), + lower_bound(), + key_comp(), and + value_comp(). The + DB_HASH specific methods are + key_eq(), + hash_funct(). +

@@ -160,7 +200,8 @@

- +

Dbstl container specific notes			Dbstl container specific + notes
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