Hello, Sinclair, you wrote: S> Hello, Gattaka, you wrote: G>> So at you already rw-lokov it is necessary to write the dictionary, it is not a lot of while. Well and how you will do locks ? Still it is necessary to invent it and to write... G>> And whether there will be at you locks about ? And escalation of locks at you will be or all will be on simple and is as consequence ineffective? And diagnostic aids at you what on a collection what will be? how to catch? And that if your collection not in operative storage entirely, but you actively work with some part, that is there is active and parts. it is quiet hindering can lie to nobody on a disk. The SQL Server gives it. And a storage fragmentation? If at you in the middle records are deleted, how many the storage collection will occupy? In a word, to write something similar to a SQL Server difficult and as a result you receive a SQL Server, only on C# and with bugs... S> you it to what? I do not offer a SQL Server, you argue about something not volume. For this purpose that does a SQL Server, the alternative, in general is not present. Only others RDBMS the same class. S> and here for this purpose to that the collection in storage suffices, the SQL Server will be . It is better to reconcile To it in advance, differently all life leaves on struggle against windmills. It I all to that SQL a high-level language. If in C# from something similar is only garbage collector, in SQL look how many all and escalation of locks etc., etc. Therefore the SQL text turns out compact and the similar code on C# was very strongly more.