Abstract: A database system may receive a query and form a plan for executing the query using a hypothetical index selected based on columns referenced by the query. The database system may compare the hypothetical index to indexes on the computing nodes of the database system. Based on the comparison, the database system may form a new index, based on the hypothetical index, on one of the computing nodes. An additional computing node may be added to the database system for the purpose of maintaining the new index. Subsequent queries having commonality with the first query may be processed on a node maintaining the first index.

Abstract: Technologies are provided for ensuring that separate network paths within a network are used for network traffic between multiple source devices and a destination device or between pairs of source and destination devices. In some solutions, network path information is determined and sent to source devices that use the network path information to encapsulate network packets that then use separate network paths for at least a portion of their paths through the network. In some solutions, separate network paths are ensured using network path separation lists that are sent to network devices to make network traffic routing decisions. In some solutions, flow description information is calculated and sent to network devices to make network traffic routing decisions to keep network flows separate.

Abstract: Technologies are provided for ensuring that separate network paths within a network are used for network traffic between multiple source devices and a destination device or between pairs of source and destination devices. In some solutions, network path information is determined and sent to source devices that use the network path information to encapsulate network packets that then use separate network paths for at least a portion of their paths through the network. In some solutions, separate network paths are ensured using network path separation lists that are sent to network devices to make network traffic routing decisions. In some solutions, flow description information is calculated and sent to network devices to make network traffic routing decisions to keep network flows separate.

Abstract: A computer implemented system and method is provided for managing sources of data transfer from a content delivery network (CDN) service provider to a client device. Illustratively, the data transfer is initialized between a first endpoint of the CDN and the client device. While the data transfer is ongoing between the first endpoint and the client device, the system receives performance information regarding alternative endpoints which may replace the first endpoint as the source for the ongoing data transfer. The performance information may be generated by the client device that probes alternative endpoints, or may be generated by dedicated monitoring nodes deployed on the network. Should a change of data transfer source be desirable, the system may cause the first endpoint to stop data transmission and cause a selected alternative endpoint to continue the ongoing data transfer to the client in accordance with a current progress of the data transfer.

Abstract: Technologies are provided for preventing transmission of cyclic redundancy check (CRC) errors, and/or other errors, within a computer network that uses cut-through forwarding of network packets. For example, counts of CRC errors can be maintained for network packets processed by network devices. When a CRC error condition is detected based on the counts of CRC errors, cut-through forwarding is disabled on at least a portion of the network (e.g., on one or more specific network ports and/or on one or more specific network devices). While cut-through forwarding is disabled, the affected portion of the network uses store-and-forward for processing network packets. When the CRC error condition no longer exists, then cut-through forwarding is re-enabled on the portion of the network.

Abstract: A proxy tunnel may be implemented to provide transparent caching for database access. A database proxy may maintain a results cache of previous queries directed to a database. Database clients may send access requests directed to a database, such as query requests or update requests, to a database proxy formatted according to an interface for the database. When a query request is received, the query request may be evaluated to determine whether the results cache maintains a valid version of the data requested by the query. If valid, the results cache may be accessed and the data sent to the client without querying the database for the data. Multiple database proxies may be implemented to provide compression and encryption when transporting data between a database client and a database, in some embodiments.

Abstract: Disclosed are various embodiments for generating a physics-based CAPTCHA. In a physics-based CAPTCHA, an object is placed within a scene so that a visually observable change occurs to the object. The scene is animated so that the visually observable change occurs to the object. Before and after imagery can be captured and used as a challenge and a response. Incorrect responses can be generated by altering the scene or object.