vertica的限制

本节介绍HP Vertica数据库中对象大小和数量的系统限制。 在大多数情况下，计算机内存和磁盘驱动器是限制因素。

Item	Limit
Number of nodes	Maximum 128 (without HP Vertica assistance).
Database size	Approximates the number of files times the file size on a platform, depending on the maximum disk configuration.根据最大磁盘配置，平台上的文件数乘以文件大小。？
Table size	2^64 rows per node, or 2^63 bytes per column, whichever is smaller. 每个节点2 ^ 64行，或每列2 ^ 63个字节，以较小者为准。
Row size	32,768,000 bytes. The row size is approximately the sum of its maximum column sizes, where, for example, a VARCHAR(80) has a maximum size of 80 bytes. 32,768,000字节。 行大小大约是其最大列大小的总和，例如，VARCHAR（80）的最大大小为80个字节。
Key size	Limited only by row size
Number of tables/projections per database	Limited by physical RAM, as the catalog must fit in memory.
Number of concurrent connections per node 每个节点的并发连接数	Default of 50, limited by physical RAM (or threads per process), typically 1024.
Number of concurrent connections per cluster 每个群集的并发连接数	Limited by physical RAM of a single node (or threads per process), typically 1024.
Number of columns per table	1600.
Number of rows per load	2^63.
Number of partitions分区数量	1024. While HP Vertica supports a maximum of 1024 partitions, few, if any, organizations will need to approach that maximum. Fewer partitions are likely to meet your business needs, while also ensuring maximum performance. Many customers, for example, partition their data by month, bringing their partition count to 12. HP Vertica recommends you keep the number of partitions between 10 and 20 to achieve excellent performance. 虽然HP Vertica最多支持1024个分区，但是很少有机构需要这样做。 更少的分区可能会满足您的业务需求，同时也确保最高的性能。 例如，许多客户按月对数据进行分区，将其分区数量设置为12. HP Vertica建议您将分区数保持在10到20之间，以实现出色的性能。
Length for a fixed-length column	65000 bytes.
Length for a variable-length column	65000 bytes.
Length of basic names	128 bytes. Basic names include table names, column names, etc.
Query length	No limit.
Depth of nesting subqueries	Unlimited in FROM, WHERE, or HAVING clause.