HelloDB

A hello kitty implementation of a NoSQL (and no frills) database server based on the WiredTiger 3.2.1 storage engine. Currently supports up to 7 fields per table 😂

Installation

Download, compile, and install the WiredTiger 3.2.1 binaries. For convenience, here is a summary of their instructions:

cd wiredtiger[-3.2.1]
./configure
make
make install

You should now have /usr/local/lib/libwiredtiger.so, /usr/local/include/wiredtiger.h, and /usr/local/bin/wt.

Clone or download hellodb.cpp.

Compile the hellodb binary:

g++ -o /path/to/hellodb /path/to/hellodb.cpp -lwiredtiger -lpthread

Configuration

Create a text file to define your table and index metadata:

#<table>
<field>
<field>
<field>

!<table>:<index>
<field>
<field>

#<table>
<field> <field> <field> <field>

!<table>:<index>
<field> <field>

For example, meta.cfg:

#customers
name age location

!customers:justname
name

!customers:location_age
location age

#transactions
item
price
date
customer

!transactions:dateAndItem
date
item

!transactions:itemAndCustomer
item
customer

Running

Start the database server (in the background with log output):

/path/to/hellodb /path/to/meta.cfg /path/to/db/folder [port default is 27000] &>/path/to/hellodb.log &

Usage

Sorry, no client yet (but there is a bulk loader). You can use TCP tools such as nc or telnet. For convenience, you can set up a Bash function like so:

hello() {
    echo $1 | nc -w1 localhost 27000
}

insert

$ hello insert]customers]Joe]28]Boston

inserted>
recno: 1

$ hello 'insert]customers]Bob]35]New York'

inserted>
recno: 2

$ hello 'insert]customers]]35]New York'

inserted>
recno: 3

$ hello insert]customers]Susan]35

inserted>
recno: 4

Note: Single quotes are not necessary if you are using echo or nc interactively instead of via Bash function.

at

$ hello at]customers]1

1>
name: Joe
age: 28
location: Boston

$ hello at]customers]2

2>
name: Bob
age: 35
location: New York

$ hello at]customers]3

3>
name:
age: 35
location: New York

$ hello at]customers]4

4>
name: Susan
age: 35
location:

find

$ hello find]customers]justname]Bob

2>
name: Bob
age: 35
location: New York

$ hello 'find]customers]location_age]New York]35'

2>
name: Bob
age: 35
location: New York

3>
name:
age: 35
location: New York

dump

$ hello dump]customers

1>
name: Joe
age: 28
location: Boston

2>
name: Bob
age: 35
location: New York

3>
name:
age: 35
location: New York

4>
name: Susan
age: 35
location:

update

$ hello update]customers]3]Jack

updated>
recno: 3

$ hello at]customers]3

3>
name: Jack
age: 35
location: New York

$ hello update]customers]4]Susan]35]Chicago

updated>
recno: 4

$ hello at]customers]4

4>
name: Susan
age: 35
location: Chicago

delete

$ hello delete]customers]3

deleted>
recno: 3

$ hello at]customers]3

Not found

$ hello find]customers]justname]Jack

Not found

shutdown

$ hello shutdown

$ ps -ef | grep hellodb
[1]+  Done hellodb 

exit

If you are using an interactive session via nc or telnet directly:

$ nc localhost 27000
find]customers]location_age]New York]35

2>
name: Bob
age: 35
location: New York

exit

$