Download Hibernate 6.2

There is a variety of definitions for terms that describe hibernation in mammals, and different mammal clades hibernate differently. The following subsections discuss the terms obligate and facultative hibernation. The last two sections point out in particular primates, none of whom were thought to hibernate until recently, and bears, whose winter torpor had been contested as not being "true hibernation" during the late 20th century, since it is dissimilar from hibernation seen in rodents.

While hibernation has long been studied in rodents (namely ground squirrels) no primate or tropical mammal was known to hibernate until the discovery of hibernation in the fat-tailed dwarf lemur of Madagascar, which hibernates in tree holes for seven months of the year.[16] Malagasy winter temperatures sometimes rise to over 30 C (86 F), so hibernation is not exclusively an adaptation to low ambient temperatures.

Download 🔥 https://fancli.com/2y3I4z 🔥

Ancient people believed that swallows hibernated, and ornithologist Gilbert White documented anecdotal evidence in his 1789 book The Natural History of Selborne that indicated the belief was still current in his time. It is now understood that the vast majority of bird species typically do not hibernate, instead utilizing torpor.[31] One known exception is the common poorwill (Phalaenoptilus nuttallii), for which hibernation was first documented by Edmund Jaeger.[32][33]

Because they cannot actively down-regulate their body temperature or metabolic rate, ectothermic animals (including fish, reptiles, and amphibians) cannot hibernate. They can experience decreased metabolic rates associated with colder environments or low oxygen availability (hypoxia) and exhibit dormancy (known as brumation). It was once thought that basking sharks settled to the floor of the North Sea and became dormant, but research by David Sims in 2003 dispelled this hypothesis,[34] showing that the sharks traveled long distances throughout the seasons, tracking the areas with the highest quantity of plankton. Epaulette sharks have been documented to be able to survive for three hours without oxygen and at temperatures of up to 26 C (79 F)[35] as a means to survive in their shoreline habitat, where water and oxygen levels vary with the tide. Other animals able to survive long periods with very little or no oxygen include goldfish, red-eared sliders, wood frogs, and bar-headed geese.[36] The ability to survive hypoxic or anoxic conditions is not closely related to endotherm hibernation.

Researchers have studied how to induce hibernation in humans.[41][42] The ability to hibernate would be useful for a number of reasons, such as saving the lives of seriously ill or injured people by temporarily putting them in a state of hibernation until treatment can be given. For space travel, human hibernation is also under consideration, such as for missions to Mars.[43]

In both cases, hibernation likely evolved simultaneously with endothermy, with the earliest suggested instance of hibernation being in Thrinaxodon, an ancestor of mammals that lived roughly 252 million years ago.[47] The evolution of endothermy allowed animals to have greater levels of activity and better incubation of embryos, among other benefits for animals in the Permian and Triassic periods. In order to conserve energy, the ancestors of birds and mammals would likely have experienced an early form of torpor or hibernation when they were not using their thermoregulatory abilities during the transition from ectothermy to endothermy. This is opposed to the previously dominant hypothesis that hibernation evolved after endothermy in response to the emergence of colder habitats.[47] Body size also had an effect on the evolution of hibernation, as endotherms which grow large enough tend to lose their ability to be selectively heterothermic, with bears being one of very few exceptions.[48] After torpor and hibernation diverged from a common proto-hibernating ancestor of birds and mammals, the ability to hibernate or go through torpor would have been lost in most larger mammals and birds. Hibernation would be less favored in larger animals because as animals increase in size, the surface area to volume ratio decreases, and it takes less energy to keep a high internal body temperature, and thus hibernation becomes unnecessary.

There is evidence that hibernation evolved separately in marsupials and placental mammals, though it is not settled. That evidence stems from development, where as soon as young marsupials from hibernating species are able to regulate their own heat, they have the capability to hibernate. In contrast, placental mammals that hibernate first develop homeothermy, only developing the ability to hibernate at a later point. This difference in development is evidence, though inconclusive, that they evolved by slightly different mechanisms and thus at different times.[49]

Bears in zoos will not hibernate if food is available, though they will slow down and sleep more than usual. Some zoo bears are fed year round, and do not hibernate. Since they do not undergo a winter weight loss like wild bears, some zoo bears can get very overweight, which is very unhealthy. Fortunately more zoos are allowing their bears hibernate during winter. Though it makes the animals unavailable for viewing, it helps the bears stay leaner and healthier.

It is the behavior of the org.hibernate.cfg.ImprovedNamingStrategy , which will convert the mixed case names to the embedded underscores name . . So if you explicitly use the name "EventLog" , it will convert to the "event_log" .

If you simply want to use the name explicitly specified in the @Table , you should use the org.hibernate.cfg.DefaultNamingStrategy . By default it is used when you instantiate your org.hibernate.cfg.Configuration object

It seems that the standard practice is to allow Hibernate to design/generate your DB schema for you, which is a new and scary concept that I am choking on. From the tutorials I read, you just add a new entity to your hibernate.cfg.xml config file, annotate any POJO you want with @Entity, and voila - Hibernate creates the tables for you. Although this is very cool, it has me wondering about a handful of scenarios:

As someone who's worked on java and hibernate in the enterprise for a long time, I have seen very few projects which use this capability. You'll see some build tools and other things do this, but for a real enterprise app, i've never seen this.

As a result, you write the SQL yourself, and you do the hibernate mappings to match. It doesn't mean your object design won't influence your SQL, but you should still always create your schema upfront.

There are 2 ways you can go about in using Hibernate. If you have good DBA or database designer, then it is better to design the database and then map it into hibernate.On the other hand if you don't have DBA and have good developer then let Hibernate generate Database for you.

Use hibernate/jpa when appropiate. A common practice when designing apps is to extract the draft and alter it manually after needs (indices etc). However, it will be a pain for you if you change the db layout from hibernate way to do things. Lots of the beauty of JPA will be lost. For tasks which require heavy performance tuning and full control - just go for reguar jdbc.

Some answers:

A. It is possible to add an index annotation : see the table annotation.

B. If you have reference tables, you may choose to have lazy fetching or eager fetching (i.e - if your tables represent a person and a its books - whether to load a person without its book, or with its books)

C. Hibernate can be used to work on existing schema. The schema might not be trivial to work with , but as other have said, you should design db only according to business needs, and not according to framework conventions

D. I would like to encourage you also to read what hibernate does "under the hood" - it uses lots of usage of proxies, which hurts performance, you must understand well the scope of session , and the usages of 1st level and 2nd level cache

.E. Following what I wrote at section D - working with triggers will cause your DB to change "under the hood" when it comes to hibernate. Consider a case where updating a record will create (using a trigger) an entry in some archiving table , and let's say this table is also annotated via hibernate

- your hibernate caching will not be aware of the change that happend outside of the application scope.

F. It is important to me to state that I'm not against Hibernate, but you should not use it for all solutions, this is a mistake I did in the past. I now work with Spring-JDBC and I'm quite pleased (for our application needs it will be hard to use Hibernate, and I assume we will consider this only in the case we need to support more than one DB flavor).

If Hibernate ORM is disabled during the build, all processing related to Hibernate ORM will be skipped,but it will not be possible to activate Hibernate ORM at runtime:quarkus.hibernate-orm.active will default to false and setting it to true will lead to an error.

If hibernate is not auto generating the schema, and Quarkus is running in development mode then Quarkus will attempt to validate the database after startup and print a log message if there are any problems.

Whether session metrics should be appended into the server log for each Hibernate session. This only has effect if statistics are enabled (quarkus.hibernate-orm.statistics). The default is false (which means both statistics and log-session-metrics need to be enabled for the session metrics to appear in the log).

Instead, normalizes the value:* upon persisting to the database, to a timestamp in the JDBC timezoneset through quarkus.hibernate-orm.jdbc.timezone,or the JVM default timezone if not set.* upon reading back from the database, to the JVM default timezone. 2351a5e196