v1.10

Document

How to Start SequoiaDB

Basic Operation

Data Model

Database Management

Aggregation

Index

Replication

Cluster

Connector

Reference

Development

Release Note

FAQ

  • Content
  • Comments
  • History

Large Object

Concept

Large Object(LOB) is a type of object that used to extend SequoiaDB' slargest record length limitation of 16MB, bringing more easy to write and read those large-size objects for users. LOBs' size has no limit currently.

Each LOB record has an OID, we can access a LOB with specific collection and OID. In not-clustered group and Hashpartitioning we can also use LOB. LOB records are not shared between shardings. When a collection is removed, the LOBs in the collection will also be deleted.

LOB records' storage format:

Each LOB record contains several shardings, the size of the sharding is limit by parameter LobPageSize (pre-defined when creating the collection). In Hash partitioning , every sharding in LOB recording will be store into discrete replica groups according to its OID and sharding number, and the hash space is the same as the hash space of the collection the LOB belongs.

Now, the LOB is stored as binary format.

Operations Supported

Operations Remarks
create The content of a LOB can't change after the record is created.
read Support seek operation.
delete no
Example
In Sdb Shell, upload local file mylob to collection foo.bar.
db.foo.bar.putLob('/opt/mylob');
In Sdb Shell, a LOB record that in collection foo.bar and has an OID of 5435e7b69487faa663000897, download it into local file mylob.
db.foo.bar.getLob('5435e7b69487faa663000897','/opt/newlob')
please login to comment.
Latest Comment
  • 2015-02-15

About Us

SequoiaDB is a financial-level distributed database vendor and is the first Chinese database listed in Gartner’s Magic Quadrant OPDBMS report. SequoiaDB has recently released version 3.0.
SequoiaDB is now penetrating the vertical sector Financial Industry quickly and had more than 50 banking clients and hundreds of enterprise customers in industries including government, telecommunication, Internet and IoT.

Beijing:
Tower R, No.8 North Star East Road, Chaoyang District, Beijing,China
Guangzhou:
Tower A, No.22 Qinglan Street, Panyu District, Guangzhou,China
Shenzhen:
Tsing Hua Tech Park, Nanshan District, Shenzhen,China
Tel:400-8038-339
E-mail:contact@sequoiadb.com