Category: NuoDB

Author: mkysel. As I explained in a previous blog post, sometimes MVCC is not sufficient and an operation needs to block out all other concurrent modifications. NuoDB is able to lock three types of lockable resources: tables, schemas, and sequences. A resource can either be locked in SHARED mode (which still allows record modification, but no metadata modification) or EXCLUSIVE which prevents any concurrent modification.EXCLUSIVE access is required for DDL that visits all records (various index operations for example) and distributed concurrent access is not possible. Exclusive access can also be used by operations that need to work around MVCC ... Read More

Author: . As I explained in a previous blog post, sometimes MVCC is not sufficient and an operation needs to block out all other concurrent modifications. NuoDB is able to lock three types of lockable resources: tables, schemas, and sequences. A resource can either be locked in SHARED mode (which still allows record modification, but no metadata modification) or EXCLUSIVE which prevents any concurrent modification.EXCLUSIVE access is required for DDL that visits all records (various index operations for example) and distributed concurrent access is not possible. Exclusive access can also be used by operations that need to work around MVCC ... Read More

Author: NuoDB. Try our Community Edition (CE) on Red Hat OpenShift!We are pleased to announce that with NuoDB v3.3, our leading distributed SQL database is now integrated into Red Hat OpenShift. This enables customers to fully develop, test, deploy and operate applications needing a SQL database fully within OpenShift. OpenShift is Red Hat’s open source container application platform based on the Kubernetes for enterprise application development and deployment. The NuoDB Community Edition (CE) is a full featured, free to use version of NuoDB, limited to three Transaction Engine (TE) processes, and one Storage Manager (SM). The CE is ideal for ... Read More

Author: . Try our Community Edition (CE) on Red Hat OpenShift!We are pleased to announce that with NuoDB v3.3, our leading distributed SQL database is now integrated into Red Hat OpenShift. This enables customers to fully develop, test, deploy and operate applications needing a SQL database fully within OpenShift. OpenShift is Red Hat’s open source container application platform based on the Kubernetes for enterprise application development and deployment. The NuoDB Community Edition (CE) is a full featured, free to use version of NuoDB, limited to three Transaction Engine (TE) processes, and one Storage Manager (SM). The CE is ideal for ... Read More

Author: mkysel. IntroLet us imagine a scenario that needs to prevent MVCC write skews... One transaction increases the salary of everyone in a department by 10%; another transaction inserts a new employee with a salary X. Since the two transactions do not conflict, MVCC does not prevent either of them from committing. After both resolve, the overall salary in the department could be above the budget. To prevent a similar situation, the application developer might want to have exclusive access to the table. NuoDB 3.2.2 exposes a new type of lock that guarantees exclusive access to a resource across the ... Read More

Author: . IntroLet us imagine a scenario that needs to prevent MVCC write skews... One transaction increases the salary of everyone in a department by 10%; another transaction inserts a new employee with a salary X. Since the two transactions do not conflict, MVCC does not prevent either of them from committing. After both resolve, the overall salary in the department could be above the budget. To prevent a similar situation, the application developer might want to have exclusive access to the table. NuoDB 3.2.2 exposes a new type of lock that guarantees exclusive access to a resource across the ... Read More

Author: mkysel. IntroAs a distributed, ACID-compliant database, we get a lot of questions about how NuoDB works, and how it compares to more well-known architectures. In particular, people want to understand how NuoDB compares to a master / master architecture, and (related) how we handle lock management. This post will discuss both. We will also discuss when shared-nothing architecture is viable and when conflicting decisions need to coordinated. In this blog post, we will discuss the concept of Chairmanship, NuoDB's answer to distributed coordination. We will prove that Chairmanship is both consistent and resilient to failure. But before we go ... Read More

Author: . IntroAs a distributed, ACID-compliant database, we get a lot of questions about how NuoDB works, and how it compares to more well-known architectures. In particular, people want to understand how NuoDB compares to a master / master architecture, and (related) how we handle lock management. This post will discuss both. We will also discuss when shared-nothing architecture is viable and when conflicting decisions need to coordinated. In this blog post, we will discuss the concept of Chairmanship, NuoDB's answer to distributed coordination. We will prove that Chairmanship is both consistent and resilient to failure. But before we go ... Read More

Author: . IntroductionTraditionally, relational databases were designed for scale-up architectures. Supporting more clients or higher throughput required an upgrade to a larger server. Until recently, this meant that implementing a read & write scale-out architecture either required a NoSQL database and abandoning traditional relational database benefits, or relying on sharding and explicit replication. There were no solutions that could scale-out and still provide complete ACID (Atomicity, Consistency, Isolation, and Durability) -compliant semantics. This tension is what inspired the NewSQL movement and ultimately led to today’s modern “elastic SQL” databases. NuoDB is an elastic SQL database designed with distributed application deployment ... Read More

Author: mkysel. IntroductionTraditionally, relational databases were designed for scale-up architectures. Supporting more clients or higher throughput required an upgrade to a larger server. Until recently, this meant that implementing a read & write scale-out architecture either required a NoSQL database and abandoning traditional relational database benefits, or relying on sharding and explicit replication. There were no solutions that could scale-out and still provide complete ACID (Atomicity, Consistency, Isolation, and Durability) -compliant semantics. This tension is what inspired the NewSQL movement and ultimately led to today’s modern “elastic SQL” databases. NuoDB is an elastic SQL database designed with distributed application deployment ... Read More