Glass-to-metal seal little lower than that of the soda-lime glass. Classically high lead containing glasses are used, but it is also possible to substitute these by multi-component glasses e.g. based on the system ---------. Glass-to-metal seal Glass-to-metal seals are a very important element of the construction of vacuum tubes, electric discharge tubes, incandescent light bulbs, glass encapsulated semiconductor diodes, reed switches, pressure tight glass windows in metal cases, and metal or ceramic packages of electronic components. Properly done, such a seal is hermetic (vacuum tight, good electrical insulation, special optical properties e.g. UV lamps). To achieve such a seal, two properties must
Hash join As with the anti-join, semi-join can also be left and right: The records are returned right after they produced a hit. The actual records from the hash table are ignored. This is more efficient when the IN table is smaller than the FROM table With this algorithm, each record from the hash table (that is, FROM table) can only be returned once, since it is removed after being returned. This is more efficient when the IN table is larger than the FROM table Hash join The hash join is an example of a join algorithm and is used in the