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Explain the role of the DESIGN_OLD.md file

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Yuriy Dupyn 2024-02-01 13:35:10 +01:00
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DESIGN.md → DESIGN_OLD.md
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@ -1,3 +1,7 @@
Note that this is a Historical Document. It is a first attempt at
figuring out basic design requirements.
# MiniSQL
## Official Description
@ -40,7 +44,7 @@ Possible usage:
```./minisql server start --db path/to/db/my-db.db --port 1433```
which will store the database as a file `path/to/db/my-db.db` and open a TCP server on port `1433`
* Then on possibly a different machine you run `./minisql client connect server_ip_address:6666` to start a client. This will open a REPL with which you can send queries/db management commands
* TODO: We should also consider writing a rust library that allows you to spin up a client that connects to the server.
* We should also consider writing a rust library that allows you to spin up a client that connects to the server.
How would the interface look like?
```
use mysql::{DB, DBConnection}
@ -69,7 +73,7 @@ which will store the database as a file `path/to/db/my-db.db` and open a TCP ser
how will the parsing output look like?
Consider something like
```
// TODO: Parser has access to all table metadata
// Parser has access to all table metadata
// Could also be called `SQLAbstractSyntaxTree`
enum Operation {
@ -132,7 +136,7 @@ type TableName = String
// Note that it is nice to split metadata from the data because
// then you can give the metadata to the parser without giving it the data.
struct TableMetaData {
name: TableName, // TODO: Is this really necessary? probably not
name: TableName,
columns: Vec<(ColumnName, DbType, ColumnPosition)>
}
@ -142,7 +146,7 @@ struct Table {
meta: TableMetaData,
rows: Rows // defined below
indexes:
BTree<ColumnName, Index> // TODO: Consider generalizing ColumnName to semething that would also apply to a pair of ColumnNames etc
BTree<ColumnName, Index>
}
type Tables = HashMap<TableName, Table>
@ -183,16 +187,13 @@ Vec<Vec<DbValue>>
* Interpreter
```
trait SqlConsumer {
// TODO:
???
}
fn interpret<T: SqlConsumer>(operation: Operation, tables: &mut Tables, consumer: T) -> () {
// TODO: lock stuff
match operation {
Select(table_name, column_selection, maybe_condition) => {
let table: Table = ...
// TODO: Wrap this into a response
select(table, column_selection, maybe_condition, consumer)
},
Insert(table_name, Vec<(ColumnName, DbValue)>) => {
@ -209,7 +210,7 @@ fn interpret<T: SqlConsumer>(operation: Operation, tables: &mut Tables, consumer
enum Response {
Selected(impl Iter<???>) // TODO: How to do this? Some reference to an iterator somehow... slice..?
Selected(impl Iter<???>) // How to do this? Some reference to an iterator somehow... slice..?
Inserted(???),
Deleted(usize), // how many were deleted
}
@ -221,7 +222,7 @@ fn select(table: Table, ColumnName
```
* TODO: Consider streaming the response to the client and not just dumping 10K rows at once.
* Consider streaming the response to the client and not just dumping 10K rows at once.